For those of you who haven't bought your G8s yet...

The GT model does not include a spare tire - neither an emergency donut tire nor a full-sized spare. Instead, in the spare tire well you will find a 12V air compressor and a can of tire sealant.

This is not acceptable to me. I plan on at least buying a donut to carry around.

My salesman was not clear on why a spare isn't included. He just said, "You can't put the donut on this car." When I pressed him, he opined that it had something to do with the car's performance. My translation is that the lawyers were concerned about liability.

Edit: the V6 models DO have a donut spare - the V8s do not.

Just thought you owners-to-be might want to know!

The G8 GT joins the Grand Prix GXP and Solstice/Solstice GXP as recent Pontiacs without a spare tire.

Maybe they couldn't source a spare wheel for the bolt pattern, offset, and brake clearance? The GT's get bigger brakes, right?

I am told that tire sealant is universally loathed by tire dealers and repair people - it's nasty, sticky stuff and very difficult to remove from the inside of the wheel.

Maybe they couldn't source a spare wheel for the bolt pattern, offset, and brake clearance? The GT's get bigger brakes, right?
Brakes are the same.

There should not be an issue with fitment - should be exactly the same as the V6 models.

Do note that if you get a spare for the GT and get a flat on one of the back tires, you will have to swap tires around to get two tires of the same size on the back. If you run two different sizes in the back you can damage the limited slip. Might be why the GT gets a can of goo, you can't run different sizes if you don't have them.

For those of you who haven't bought your G8s yet...

The GT model does not include a spare tire - neither an emergency donut tire nor a full-sized spare. Instead, in the spare tire well you will find a 12V air compressor and a can of tire sealant.

This is not acceptable to me. I plan on at least buying a donut to carry around.

My salesman was not clear on why a spare isn't included. He just said, "You can't put the donut on this car." When I pressed him, he opined that it had something to do with the car's performance. My translation is that the lawyers were concerned about liability.

Edit: the V6 models DO have a donut spare - the V8s do not.

Just thought you owners-to-be might want to know!

hahaha. It doesnt have a spare because 1) the vehicle has an equal 50/50 weight distribution and the spare would throw this off and 2) buy any modern sports car today and it will not have a spare tire either. the flat tire kit is the wave of the future.

hahaha. It doesnt have a spare because 1) the vehicle has an equal 50/50 weight distribution and the spare would throw this off and 2) buy any modern sports car today and it will not have a spare tire either. the flat tire kit is the wave of the future.

The car does not have 50/50 weight distribution. It is nose-heavy, at 51F/ 49R. A spare in the trunk would only improve that.

There is no spare because of (1) overall weight savings (2) meeting a price point, and (3) possible liability from using a donut with 360 HP.

The trunk has a well that's large enough to accommodate a full-sized spare, so the car certainly was not engineered with no spare in mind.

Do note that if you get a spare for the GT and get a flat on one of the back tires, you will have to swap tires around to get two tires of the same size on the back. If you run two different sizes in the back you can damage the limited slip. Might be why the GT gets a can of goo, you can't run different sizes if you don't have them.

Do you think that running a slightly different-size tire for, say, 50 miles or less would harm a LSD?

The car does not have 50/50 weight distribution. It is nose-heavy, at 51F/ 49R. A spare in the trunk would only improve that.

There is no spare because of (1) overall weight savings (2) meeting a price point, and (3) possible liability from using a donut with 360 HP.

The trunk has a well that's large enough to accommodate a full-sized spare, so the car certainly was not engineered with no spare in mind.

well thats what it states in the official dealer training by GM. It does, in fact, have 50/50 weight dist.

well thats what it states in the official dealer training by GM. It does, in fact, have 50/50 weight dist.

And it may very well. I'd suggest that putting an additional 20 pounds of donut tire in the trunk is going to have very little effect on the weight distribution of a 4,000-pound car. Or 3,995 if you want to be exact.

Back to the subject at hand, I'm still gonna get a spare!

And since I'm such a skinny little mofo, I can add a spare tire's weight to the car and still have a better power-to-weight ratio than you! :laugh:

Does anyone know if Run-Flats require special wheels or can they replace any tire on any wheel? That might be a solution, although I'm sure they cost more. BMW uses the Run-Flats on many of it's newer models.

Awaiting G8 GXP 6MT

z06 has runflats as well.. they're pricey.

Does anyone know if Run-Flats require special wheels or can they replace any tire on any wheel? That might be a solution, although I'm sure they cost more. BMW uses the Run-Flats on many of it's newer models.

Awaiting G8 GXP 6MT

From what I have been told, you can use run flats with anywheels. However, as stated by TheGeneral, run flat tires are very expensive. My dad's CTS-V has run flats and it cost him a fortune to replace his tires.

Donuts are cheap! :angel:

The only reasons for having no spare are either cost or a marketing angle. The HSV Clubsport R8 which run 19" x 8" fronts and 19 x 9.5 rears has a full sized (19 x 8) spare wheel.

The only reasons for having no spare are either cost or a marketing angle. The HSV Clubsport R8 which run 19" x 8" fronts and 19 x 9.5 rears has a full sized (19 x 8) spare wheel.

Thank you!

I just called my nearby Discount Tire dealer. Seems they can't sell the compact spares, so I'll likely end up with some full-size generic tire/wheel combination with the correct bolt pattern and tire diameter.

Oh, since the GT doesn't come with a spare, it doesn't come with a jack, either, or a lug wrench. :eek2:

Find a used GTO 17" - it will fit (or a BMW 5 series).

Aren't the lugs a different size on the GTO's? 12mm vers 14mm? I also thought the hub centric part of the GTO wheel is smaller than the G8 wheel.

Nope, the same. The GTO "hole" is bigger, so it will fit.

Thank you!

I just called my nearby Discount Tire dealer. Seems they can't sell the compact spares, so I'll likely end up with some full-size generic tire/wheel combination with the correct bolt pattern and tire diameter.

Oh, since the GT doesn't come with a spare, it doesn't come with a jack, either, or a lug wrench. :eek2:

If you are that worried about a flat, spend the $$ and buy a set of run flats. Oh, and keep up the payments on your OnStar subscription, they can hook you up with someone to come get you in case of a flat and tow you to a service dealer if need be.:angel:

Might also have something to do with keeping the car under $30K.

i know JHP got some OEM Spare Tire sets, its ~$130 +(shipping $40 if stock in CA)

Might also have something to do with keeping the car under $30K.

Might also have to do with marketing/advertising.

Car weight is 3,995 pounds.

Seems to me they were really trying hard to keep it under 4,000 pounds.

Adding a spare could make it 4,020 pounds.

Which looks bad to some once it passes the 4,000 mark lol

Nope, the same. The GTO "hole" is bigger, so it will fit.

What about the lugs? They are still different. 12mm vers 14mm.

See post #34 of this thread http://www.g8board.com/forums/showthread.php?t=21&page=2

The lugs on a GTO and a G8 are two different sizes. One is 12mm the other is 14mm. So A GTO wheel will fit on a G8, but you will need special lug nuts cause the lug hole in the wheel is smaller. Or have the lug hole in the wheel made larger to fit the 14mm lugs from a G8.

If you are that worried about a flat, spend the $$ and buy a set of run flats. Oh, and keep up the payments on your OnStar subscription, they can hook you up with someone to come get you in case of a flat and tow you to a service dealer if need be.:angel:
Dang, run-flats cost $400 - $500 each. I don't think I'm going to rush out and spend $2,000 on a set of run-flats when I can take care of the problem for a couple of hundred bucks.

Do you think that running a slightly different-size tire for, say, 50 miles or less would harm a LSD?

Depends on the size difference, but I wouldn't do it. I would think it would also depend on the type of limited slip used (clutch, cone, etc.). I am not sure which type is used in the G8.

Depends on the size difference, but I wouldn't do it. I would think it would also depend on the type of limited slip used (clutch, cone, etc.). I am not sure which type is used in the G8.

Right. I think the rear end is a ZF but I don't know anything more than that.

I'm probably going to end up with a full-sized spare anyhow so it shouldn't be an issue.

A. The front and rear tires are the same size.
B. The outside diameter of all G8 tires are effectively the same (approx. 26.7 inches).
C. The brakes are all the same size.

There is absolutely no reason I can see why the base G8 spare would not work perfectly fine on a G8 GT, with or without sport package 19-inch wheels. The biggest inconvenience would be if you had to mount the spare, the spare tire cover in the trunk wouldn't close, since the 19-inch wheel/tire is significantly wider.

I know I sound like a luddite here, but here's my imaginary scenario:

Driving with my wife to Possum Kingdom Lake, 70 miles west of Fort Worth, just the two of us - we've farmed the kids out to my parents so we'll have a weekend alone. We're in Zaphod's G8 GT. This is usually a drive of about 1 hour and 20 minutes.

20 miles from our destination, out past West Bumf**k, Texas, I pick up a nail in the sidewall, a hole too big for the sealant to work.

Option (1) - No spare: I call Onstar, they send a tow truck, and haul us all the way back to Fort Worth since that's where the nearest dealers of any size are. Get the car off the truck, put our gear in Mrs. Zaphod's SUV, and head back out. Total ET to get to the lake: 4-1/2 hours.

Option (2) - Spare: Replace flat tire with spare, continue to lake. Total ET to get there: 1 hour, 40 minutes.

It just seems like a no-brainer to me.

A. The front and rear tires are the same size.
B. The outside diameter of all G8 tires are effectively the same (approx. 26.7 inches).
C. The brakes are all the same size.

There is absolutely no reason I can see why the base G8 spare would not work perfectly fine on a G8 GT, with or without sport package 19-inch wheels. The biggest inconvenience would be if you had to mount the spare, the spare tire cover in the trunk wouldn't close, since the 19-inch wheel/tire is significantly wider.Um, the brakes on the V6 are smaller diameter than the V8, so the V6 temp spare may NOT fit over the V8 brakes.

And the 18's and 19's are both 8" wide wheels and both 245 tread width. Why are you saying 19's are wider???

And the 18's and 19's are both 8" wide wheels and both 245 tread width. Why are you saying 19's are wider???

You lost me here. Who are you quoting?

Um, the brakes on the V6 are smaller diameter than the V8, so the V6 temp spare may NOT fit over the V8 brakes.

There is nothing in any of Pontiac's literature that indicates any difference between the V6 and V8 models' brakes.

There is nothing in any of Pontiac's literature that indicates any difference between the V6 and V8 models' brakes.

The G8 product brouchure includes this line in the Brakes section, "On G8 GT, includes larger front and rear rotors".

In the text on page 22, "G8 GT's discs are one inch larger".

The online product guide available to dealerships, which I think has been linked on this site, makes a similar statement.

Also included in Salesperson training materials.

The G8 product brouchure includes this line in the Brakes section, "On G8 GT, includes larger front and rear rotors".

In the text on page 22, "G8 GT's discs are one inch larger".

The online product guide available to dealerships, which I think has been linked on this site, makes a similar statement.

Also included in Salesperson training materials.
Ah - thanks! That clears up part of the mystery.

Um, the brakes on the V6 are smaller diameter than the V8, so the V6 temp spare may NOT fit over the V8 brakes.

I stand corrected, if in fact the GT comes with larger brake rotors. However, the GT comes standard with 18-inch wheels, so it seems to me the standard G8 spare should fit fine.

And the 18's and 19's are both 8" wide wheels and both 245 tread width. Why are you saying 19's are wider???

Very good point! So it shouldn't be a problem.

The car does not have 50/50 weight distribution. It is nose-heavy, at 51F/ 49R. A spare in the trunk would only improve that.

There is no spare because of (1) overall weight savings (2) meeting a price point, and (3) possible liability from using a donut with 360 HP.

The trunk has a well that's large enough to accommodate a full-sized spare, so the car certainly was not engineered with no spare in mind.



400HP GTOs came with donuts.

400HP GTOs came with donuts.
Well, dammit, why can't I have a donut? :eek2: :eek2: :eek2:

I stand corrected, if in fact the GT comes with larger brake rotors. However, the GT comes standard with 18-inch wheels, so it seems to me the standard G8 spare should fit fine.

Yes, but to make things more interesting, the spare tire is a 17" wheel, 17"x4".

I am told that tire sealant is universally loathed by tire dealers and repair people - it's nasty, sticky stuff and very difficult to remove from the inside of the wheel.
Don't use any kind of "fix-a-flat" aerosol goop if you run Michelin Pilot Sport A/S tires. Not only does it void the warranty, but ruins the tire.

Free OnStar for a year.....NO Problem. If you can afford 31K for this car hoprfully you can afford to keep OnStar for a few years. I think It's worth it just for the "stolen car" GPS locator.

Now, who will be the first to claim that smart car thieves always drive the car into a tunnel after they swipe it? :gr_jest:

I'm gonna buy a spare. It'll save time and likely money.

I'm gonna buy a spare. It'll save time and likely money.

Me too. What's the easiest way to buy something that fits? Order a GTO spare?????

Now, who will be the first to claim that smart car thieves always drive the car into a tunnel after they swipe it? :gr_jest:

Bahhaaaa! And never drive out again....EVER!:gr_jest::gr_jest:

I stand corrected, if in fact the GT comes with larger brake rotors. However, the GT comes standard with 18-inch wheels, so it seems to me the standard G8 spare should fit fine.See the quote below, the V6 G8 spare is not a full sized wheel, therefor it may not clear the V8 brakes, and based on what small dealer says below, it is a 17" wheel, so good luck on the V8 with that!

Yes, but to make things more interesting, the spare tire is a 17" wheel, 17"x4".

Yes, but to make things more interesting, the spare tire is a 17" wheel, 17"x4".

Sneaky suckers! Looks like all my assumptions were WRONG! :slap:

I know I sound like a luddite here, but here's my imaginary scenario:

Driving with my wife to Possum Kingdom Lake, 70 miles west of Fort Worth, just the two of us - we've farmed the kids out to my parents so we'll have a weekend alone. We're in Zaphod's G8 GT. This is usually a drive of about 1 hour and 20 minutes.

20 miles from our destination, out past West Bumf**k, Texas, I pick up a nail in the sidewall, a hole too big for the sealant to work.

Option (1) - No spare: I call Onstar, they send a tow truck, and haul us all the way back to Fort Worth since that's where the nearest dealers of any size are. Get the car off the truck, put our gear in Mrs. Zaphod's SUV, and head back out. Total ET to get to the lake: 4-1/2 hours.

Option (2) - Spare: Replace flat tire with spare, continue to lake. Total ET to get there: 1 hour, 40 minutes.

It just seems like a no-brainer to me.

Trust me, Option 2 is the better way. I live west of Fort Worth near West BFE, and I can relate to your pain.

Mrs. Spanielrage had the unfortunate experience of a flat on her Cadillac SRX. It took the dealer (Frank Kent Cadillac, to name names) forever to get to her, then the gorilla they sent didn't even know where the SRX jack was or how to lower the spare. Mrs. Spanielrage had to read the owners manual and teach the gorilla how to change the tire. 1 1/2 hours later, she's finally back on the road, wishing she had just done it herself. Makes you question the worth of OnStar, period.

i know JHP got some OEM Spare Tire sets, its ~$130 +(shipping $40 if stock in CA)
Genuine GM VE Commodore Space saver is 17 x 5, $179 delivered
Heres the link to the G8 Parts direct web site for the space saver... http://www.jhp.com.au/g8partsdirect/WheelsSpS.htm

http://www.wheeltrader.com.au/user_images/1584027.jpg

O well its just more weight in a alreayd heavy car. I would have ditched it anyway :gears:

Trust me, Option 2 is the better way. I live west of Fort Worth near West BFE, and I can relate to your pain.

Mrs. Spanielrage had the unfortunate experience of a flat on her Cadillac SRX. It took the dealer (Frank Kent Cadillac, to name names) forever to get to her, then the gorilla they sent didn't even know where the SRX jack was or how to lower the spare. Mrs. Spanielrage had to read the owners manual and teach the gorilla how to change the tire. 1 1/2 hours later, she's finally back on the road, wishing she had just done it herself. Makes you question the worth of OnStar, period.

That's exactly what I'm talking about. Why go through all that BS if you can just change the *#!!@* tire?

Genuine GM VE Commodore Space saver is 17 x 5, $130
Where can I get that tire? Will it fit a GT?

The car does not have 50/50 weight distribution. It is nose-heavy, at 51F/ 49R. A spare in the trunk would only improve that.

There is no spare because of (1) overall weight savings (2) meeting a price point, and (3) possible liability from using a donut with 360 HP.

The trunk has a well that's large enough to accommodate a full-sized spare, so the car certainly was not engineered with no spare in mind.

I find that Hard to believe, since all GTO coupes came with a spare donut tire. 17" x4"

i guess i'm the only person who is gonna call roadside service

If you are that worried about a flat, spend the $$ and buy a set of run flats. Oh, and keep up the payments on your OnStar subscription, they can hook you up with someone to come get you in case of a flat and tow you to a service dealer if need be.:angel:
I'm sure some of you will have a laugh about this. Last monday I clipped a curb too close and ripped a chunk out of the side of the RR tire. AHHAHAAAHAHAAAA! There, I had a laugh too.

Parked in a drug store lot, called OnStar and they had a service truck there in a fairly short while. Only problem? They wanted it towed to a Pontiac dealer. My guess was that any dealer that had a replacement 19" might be within, oh, maybe 2000 miles.

So when the tow truck dude showed up and we had BS'ed for 45 min. about the car, I said "let's just run over to Discount Tire. Just happened they had 4 Potenzas to choose from. :p

They had already ordered a replacement Michelin when I got there, and had one of the old Bridgestones on, balanced and I was out the door in about 20 min.

No charge for the tow, no cost for the tire. Just a real PITA. :banghead:

Why was the tire free? Is that an Onstar benefit or something else?

Why was the tire free? Is that an Onstar benefit or something else?
Ah, sorry me no esplain so good.

I always add the full road hazard option for high-end tires like the Michelins. So since it was a brand new $350 tire that I ripped the side out of they replace it for no additional charge. They put one of the Potenza's I had just traded in on as a loaner until the Michelin comes up from the So. Cal. warehouse.

For those of you who haven't bought your G8s yet...

The GT model does not include a spare tire - neither an emergency donut tire nor a full-sized spare. Instead, in the spare tire well you will find a 12V air compressor and a can of tire sealant.

This is not acceptable to me. I plan on at least buying a donut to carry around.

My salesman was not clear on why a spare isn't included. He just said, "You can't put the donut on this car." When I pressed him, he opined that it had something to do with the car's performance. My translation is that the lawyers were concerned about liability.

Edit: the V6 models DO have a donut spare - the V8s do not.

Just thought you owners-to-be might want to know!

That's ridiculous. We get a full size alloy spare wheel which matches the 4 o the car. They must be cutting costs for the US market. We'd never put up with that. A can of crap and a pump wouldn't help you when your two thousand miles from a tyre shop.

For those of you who haven't bought your G8s yet...

The GT model does not include a spare tire - neither an emergency donut tire nor a full-sized spare. Instead, in the spare tire well you will find a 12V air compressor and a can of tire sealant.

This is not acceptable to me. I plan on at least buying a donut to carry around.

My salesman was not clear on why a spare isn't included. He just said, "You can't put the donut on this car." When I pressed him, he opined that it had something to do with the car's performance. My translation is that the lawyers were concerned about liability.

Edit: the V6 models DO have a donut spare - the V8s do not.

Just thought you owners-to-be might want to know!
you do have roadside assistance for free so that may help if you get a flat!!!!!

The G8GT at the local car show this weekend has a 17" spare in the trunk. I couldn't convince the reps to let me try to fit it on.

An update on my insistence on having a spare tire:

I went to the nearby Discount Tire store during lunch today. The guy pulled one of the wheels and measured the bolt pattern - verifying that it is 5 X 120mm.

He's going to do a little research, and find a 18" wheel with the correct bolt pattern and a tire that has the correct outside diameter. We'll do a trial fit of the wheel alone to make sure that it mounts OK and clears the calipers.

In the meantime I purchased a tire-life road hazard warranty and rotate/balance service. The cost of those services for all four tires is considerably less than the cost of one new tire.

I wouldn't be so concerned, but I pick up nails and screws about once a year, like clockwork, and it's only a matter of time before I'll be glad there's a spare in the trunk.

A friend who recently sold his car gave me a scissor jack that he had taken out of it so I'm good there, too.

I looked on the Holden site and the Commodores there are offered with a full sized spare, even the 19" equipped SS. So, why not just order a wheel from Pontiac, and a tire, and then the jack and wrench assembly from the V6 car and you are good to go. That is what I plan to do anyhow.

I looked on the Holden site and the Commodores there are offered with a full sized spare, even the 19" equipped SS. So, why not just order a wheel from Pontiac, and a tire, and then the jack and wrench assembly from the V6 car and you are good to go. That is what I plan to do anyhow.

sounds like the best idea so far...

I looked on the Holden site and the Commodores there are offered with a full sized spare, even the 19" equipped SS. So, why not just order a wheel from Pontiac, and a tire, and then the jack and wrench assembly from the V6 car and you are good to go. That is what I plan to do anyhow.

sounds like the best idea so far...
That's a good idea, but I'm afraid to ask what Pontiac wants for the 19" alloy fitted with the Potenza summer tire. My hope is to have a usable spare that won't burn too big a hole in my debit card.

This is a great reason to get aftermarket wheels, buy an extra tire and keep an OEM in the back as the spare. ;) I told the fiancee it was a necessity LMAO

Where can I get that tire? Will it fit a GT?
contact JHP for more info
http://www.jhp.com.au/contact-form-main.php

Guys, if you are not running with a spare, I highly recommend spending 5 bucks for a tire plug kit at the auto parts store. When you get a hole in the tire, you put glue on the plug and use the provided tool to push it through. It will seal a MUCH bigger hole than sealant. I’ve put about 80k miles on my tbird with no spare tire. I really did it just to save weight. I carry an air compressor, a plug kit, and a can of Fix a Flat.

The plugs have never let me down. Even though a patch from the inside is best, the plugs have lasted for the life of the tire.

Of course if you hit something and damage the sidewall, or put a big hole in the tire, it’s tow truck time if you don’t have a spare. But the plug kit is a good tool to have in your arsenal.

Guys, if you are not running with a spare, I highly recommend spending 5 bucks for a tire plug kit at the auto parts store. When you get a hole in the tire, you put glue on the plug and use the provided tool to push it through. It will seal a MUCH bigger hole than sealant. I’ve put about 80k miles on my tbird with no spare tire. I really did it just to save weight. I carry an air compressor, a plug kit, and a can of Fix a Flat.

The plugs have never let me down. Even though a patch from the inside is best, the plugs have lasted for the life of the tire.

Of course if you hit something and damage the sidewall, or put a big hole in the tire, it’s tow truck time if you don’t have a spare. But the plug kit is a good tool to have in your arsenal.Agreed, I carry the plug kit, compressor, and a can of fix a flat, I have had (yes once only) two flats at the same time, and luckily had the fix a flat in the car so I was able to go, since then I also carry the tire plug kit, they are cheaper than the fix a flat.

As for my spare, I will use one of my summer's when I get a set of snows on 18's and the snow for the spare next summer.

An update on my insistence on having a spare tire:

I went to the nearby Discount Tire store during lunch today. The guy pulled one of the wheels and measured the bolt pattern - verifying that it is 5 X 120mm.

He's going to do a little research, and find a 18" wheel with the correct bolt pattern and a tire that has the correct outside diameter. We'll do a trial fit of the wheel alone to make sure that it mounts OK and clears the calipers.

In the meantime I purchased a tire-life road hazard warranty and rotate/balance service. The cost of those services for all four tires is considerably less than the cost of one new tire.




Sorry to hijack the thread, but I have a burning question Zaphod...What kind of wheels are you getting? (I ask because I am wheel shopping and would prefer to have something different that the other DFW people)

Sorry to hijack the thread, but I have a burning question Zaphod...What kind of wheels are you getting? (I ask because I am wheel shopping and would prefer to have something different that the other DFW people)
Cashed, I'm not replacing the 19" OEM wheels - I'm just looking for a single wheel to carry a spare tire. But I'll let you know what that turns out to be.

I called the nearest Pontiac parts department and talked with one of the parts guys. He looked up the donut spare (comes standard on the V6 models) and it does not pop up as being specific to the V6 configuration. Neither does the scissor jack. He asked that I come in and he can run the car's VIN to see if Pontiac puts any flags in their parts database regarding the donut spare. I'm also going to ask him to price a single 19" alloy.

I haven't heard back from Discount Tire. They are trying (unsuccessfully it seems) to get specific specs for the wheel from the Pontiac guys (backspacing particularly) to see what a suitable spare wheel would be.

Who would have thought it would have to be this hard?

Oh, and great recommendation for a tire plug kit, Jlockhart. I'd much rather do that than spray a can of that sticky **** into the tire.

I haven't heard back from Discount Tire. They are trying (unsuccessfully it seems) to get specific specs for the wheel from the Pontiac guys (backspacing particularly) to see what a suitable spare wheel would be.

Who would have thought it would have to be this hard?

Unfortunantly we are relying on the dealership AND my favorite foe...Discount Tire. I have had so many hit or miss experiences with those guys when searching for wheels, tires, spares, etc. Keep me posted on what you find as I too want a spare in the trunk.

Unfortunantly we are relying on the dealership AND my favorite foe...Discount Tire. I have had so many hit or miss experiences with those guys when searching for wheels, tires, spares, etc. Keep me posted on what you find as I too want a spare in the trunk.

I'll be sure to let you know.

contact JHP for more info
http://www.jhp.com.au/contact-form-main.php
Thanks!

SPARE TIRE FIX FOR G8 GT!

I placed one of my GTO 17'take-off wheels on both front and back hub. There is a clearance
problem on the front, NOT with the brake rotors, but with a strut tower brace. This is because of the 48 mm offset. If one would use a 40mm offset wheel it would fit just fine. The temporary solution is to use a couple of 5/8" washers as spacers on each lug. This will at least get you to a tire store or home. Don't think you want to drive cross-country.... The back hubs have plenty of clearance for the 17" wheel to work without spacers. I realize the GTO tires are slightly smaller. A long-term inexpensive solution would be to buy the cheapest BMW aftermarket 17" or 18" wheel with 40 mm offset and mount the correct height tire. BOTH the 17" GTO rim and the 19" G8 rim fit in the tire well in the trunk.

I also changed the stock 22mm (7/8") lugs for some 19mm (3/4") closed chrome lugs from TireRack, for $1.00 each plus shipping. These lugs look much better than the stock ones with the black plastic caps, and can be used on future aftermarket wheel purchases.

Also purchased an inexpensive (under $20.) sissors jack that fits inside the tire well.

Now, I just have to teach my wife to change the tire so I can stay inside the car!

RRM

Excellent post, Rob - thanks!

I see that The Tire Rack (http://www.tirerack.com) now has the G8 in their wheel database, and when you select wheels by car model, almost all of the wheels found for the G8 GT have either 40mm or +39mm offsets. That's the key piece of information, I think, and it agrees with what you have found.

SPARE TIRE FIX FOR G8 GT!

Now, I just have to teach my wife to change the tire so I can stay inside the car!

RRM

The best part of your post...when you figure out how to make that happen, be sure to start another thread! :popcorn2:

The reason that the stock 18's and 19's work with 48mm offset is that their diameter is greater that the strut brace. I.E. they clear it because the rim is above it at that point. Any 40mm offset wheel will clear the brace by being outside of it.

My plan is to find a G8 takeoff wheel at some point and use it. One other thing, any wheel without TPMS will make the tire pressure system go wacky! Mainly wanted to CMA on our trip up north for the summer.

RRM

Here's how I ended up taking care of the problem.

Discount Tire was slow in responding and when they did I didn't feel 100% comfortable with what the guy found. (18" wheel w/20mm offset, 245/45 tire, slightly different ride height, only off by 4/10". They wanted $315 + tax.

Out of curiosity I called the dealer parts guys to get a quote on a single OEM 19" alloy. They want $459 + $50 core fee + tax. Not including a tire.

I ended up finding something acceptable at Tire Rack online. I ordered an ASA JH8 wheel, 19 X 8.5, 40mm offset, fitted with a Sumitomo P245/40ZR19 HTR Z III XL, mounted, balanced, and shipped for $380.

This is more than I wanted to spend on a spare but it's worth every penny to have one.

Anybody checked on the 2008 Cadillac CTS spare and jack kit? It's an 18" donut with the same bolt pattern as the G8 (just don't know if it will clear the rotors). My father bought one from his Cadillac dealer for $350 (yeah, it's a $250 order option, but he took what was on the lot and had to pay the parts department price).

So.... I'm asking a dumb question here. Yes, I could have answered it if I had done enough research. But, get over it. Just answer me................



Will the V6 spare fit? Is the bolt pattern the same?

Does Anyone Know If A Spare Will Actualy Fit In The Trunk Well Without Removing The Compressor Stuff. Or Is A Donut They Way To Go. Where Can I Buy A Wheel And Tire In New Jersey

i guess i'm the only person who is gonna call roadside service

I'm with Russo, but couldn't you just buy any 16" rim with a 60+ series tire that fit the car, just make sure the over all diameter on all 4 is the same. You don't need to pay a lot for a spare.

Does Anyone Know If A Spare Will Actualy Fit In The Trunk Well Without Removing The Compressor Stuff. Or Is A Donut They Way To Go. Where Can I Buy A Wheel And Tire In New Jersey

That's what I'm waiting to see. If it does, the cheapest 19" rim and tire that Tirerack has will be ordered first thing after I see pictures of one in someone's trunk.

I'm with Russo, but couldn't you just buy any 16" rim with a 60+ series tire that fit the car, just make sure the over all diameter on all 4 is the same. You don't need to pay a lot for a spare.

I could be wrong but I am not sure that a 16" rim will clear the brakes.

When I installed a 17" from my GTO, the clearance was very close on the front calipers so I doubt a 16" wheel would work. Also, the offset has to be around 40mm. That was the problem on the front, with the 48mm offset of a stock 17" GTO wheel. 18" and 19" wheels do not have this problem. The other issue is that the GTO wheel is NOT hubcentric as the hub hole is larger than the G8. The 19" wheel will fit in the trunk tirewell, but not with the styrofoam packaging that holds the pump and fixaflat. Plenty of room for everything when it is removed.

The TPMS is also going to be an issue, until the original wheel is back on the car. Anyone find out how much extra TPMS modules cost?

RRM

The TPMS is also going to be an issue, until the original wheel is back on the car. Anyone find out how much extra TPMS modules cost?
Rob, I think that the TPMS is only an issue in that any wheel without a sensor will not report to the system, but the others still will. For a short-term spare it's not an issue for me.

Is there a place to put a spare tire in the GT? If so I am going to take out the spare in my GTO before trading it in.

The same place the V6 owners keep theirs.

The TPMS is also going to be an issue, until the original wheel is back on the car. Anyone find out how much extra TPMS modules cost?

RRM

That's not really an issue. It will just set off the tpms light. The car won't drive differently. At least it doesn't on my truck. My light stays on. I don't have any tpms in the tires on it and the only real problem is if the light bothers you.

The same place the V6 owners keep theirs.

Sorry, have not seen a G8 yet, none here anywhere close.

Sorry, have not seen a G8 yet, none here anywhere close.

When you open the trunk you can lift up the carpeted flooring and there is a place underneath for a spare.

run flats are expensive, heavier than a similar tire by 4-5 lbs each, and hurt handling and such.

Get yourself a GTO spare http://cgi.ebay.com/ebaymotors/04-06-OEM-GTO-Mini-Spare-ALSO-97-04-Corvettes_W0QQcmdZViewItemQQcategoryZ66483QQihZ001 QQitemZ110243671269QQrdZ1QQsspagenameZWDVW

I ended up finding something acceptable at Tire Rack online. I ordered an ASA JH8 wheel, 19 X 8.5, 40mm offset, fitted with a Sumitomo P245/40ZR19 HTR Z III XL, mounted, balanced, and shipped for $380.
I wanted to give you guys an update.

I received the mounted and balanced ASA wheel & Sumitomo tire from Tire Rack. It came with lug nuts, a lug nut socket, and a centering ring.

I did a trial fit last night on the front and it fit perfectly. The spare tire well is more than big enough to hold a full-size spare. I took out the compressor and sealant, and put in a scissor jack that a friend salvaged from a Subaru wagon (works perfectly, too - it's what I used to jack up the car). That along with a breaker bar and a 22mm socket for the OEM lugs and I should be good to go.

Oh, by the way, here's another oddity:

The compressor that comes in the GTs (instead of the spare) has a tire sealant canister integrated into the compressor. I don't think the compressor can be used without the sealant canister.

You have to wonder who thinks this stuff up. :banghead::rant::banghead:

Edit: You can use the compressor without the sealant canister. I stand corrected. Guess I'll be throwing it in the spare tire well, too.

i know JHP got some OEM Spare Tire sets,

JHP (www.g8partsdirect.com) are shipping some space saver 17" wheel & tires to suit G8 to our California warehouse, the cost is $179

If there is enought interest in the G8 GT sports wheel 19 x 8 to be used as a spare we can put together a special and ship direct to your door ?

Cashed, I'm not replacing the 19" OEM wheels - I'm just looking for a single wheel to carry a spare tire. But I'll let you know what that turns out to be.

I called the nearest Pontiac parts department and talked with one of the parts guys. He looked up the donut spare (comes standard on the V6 models) and it does not pop up as being specific to the V6 configuration. Neither does the scissor jack. He asked that I come in and he can run the car's VIN to see if Pontiac puts any flags in their parts database regarding the donut spare. I'm also going to ask him to price a single 19" alloy.

I haven't heard back from Discount Tire. They are trying (unsuccessfully it seems) to get specific specs for the wheel from the Pontiac guys (backspacing particularly) to see what a suitable spare wheel would be.

Who would have thought it would have to be this hard?

Back spacing is 48P, it should be listed on the back of the stock wheel.
Same lug nut spacing as '04-'06 GTO but the centre hub size is different.

JHP (www.g8partsdirect.com) are shipping some space saver 17" wheel & tires to suit G8 to our California warehouse, the cost is $170

If there is enought interest in the G8 GT sports wheel 19 x 8 to be used as a spare we can put together a special and ship direct to your door ?

Just let me know how much, I'm intrested and need a spare!

JHP (www.g8partsdirect.com) are shipping some space saver 17" wheel & tires to suit G8 to our California warehouse, the cost is $170

If there is enought interest in the G8 GT sports wheel 19 x 8 to be used as a spare we can put together a special and ship direct to your door ?

So, the space saver will fit on the GT ????

Edit: You can use the compressor without the sealant canister. I stand corrected. Guess I'll be throwing it in the spare tire well, too.

Yep, good to keep the compressor, too. I had to put the donut on the GTO a couple of weeks ago. The donut was flat when I put it on. Good thing I had the flat(s) in the driveway as I could use my air compressor at the house. That would have sucked had I had to make the change on the side of the road only to find the donut was flat, too.

Yep, good to keep the compressor, too. ...... That would have sucked had I had to make the change on the side of the road only to find the donut was flat, too.
Been there, done that. :cursin:

I am told that tire sealant is universally loathed by tire dealers and repair people - it's nasty, sticky stuff and very difficult to remove from the inside of the wheel.

Not only hated, but impossible to replace!

Had a flat (small nail) over the weekend so I used the tire sealant. It worked as advertised but now I can't replace the empty cannister. Pontiac doesn't even have a Part Number for the Dealer to order it!

Guess I have no spare, no jack, no lug wrench and no hope if I get another flat.

Hello, Road Side Assistance?

Had a flat (small nail) over the weekend so I used the tire sealant. It worked as advertised but now I can't replace the empty cannister. Pontiac doesn't even have a Part Number for the Dealer to order it!

Bumper to Bumper Warranty. Why get a new canister when the dealer can buy you an entirely new pump setup? :)

Has anyone had any luck with anything cheaper?

Dealer was able to locate the replacement sealer with the help of Pontiac. Cost is $26.50 for the cannister. Still haven't received it yet, GM Parts had a computer problem, so they said!

Supposed to get it Monday, a week after first calling.

Is there a provision to secure the spare? I wouldn't want it loose in the even of an accident.

I got a nail the other day, and used a plug kit to fix it. I did forget they are kind of a pain to use on the side of the road. You've got to find the nail or hole which usually involves moving the car until the tire is in the right position. And then you've got to remove the nail before you can plug it. So I guess needle nose pliers and a flashlight are required as well. Late at night with the family in the car, I might just add a little fix a flat, air up the tire and see if it holds air first, whether the tire guy likes it or not.

Fix a flat would work just as well as the canister right? Although if GM is paying, might as well let them replace the canister.

Hmmm... I'm wondering if the GXP will have the same deal, or a spare:err:

Hmmm... I'm wondering if the GXP will have the same deal, or a spare:err:

I doubt it has a spare. I'm holding out for the GXP (I also found a dealer who would honor GM S pricing :hail:), and I've had 3 tires on 2 vehicles ruined in the past 6 months, so this is a big concern for me (see my earlier OnStar rant:mad:). The question is with the bigger front brakes, will the Commodore or GTO 17" compact spares work? If not, the Cadillac CTS spare should work. The CTS spare kit (GM #159179359) includes an unmounted 18" donut (T135/70R18) with the same bolt pattern as the G8, along with a jack and lug wrench. Weight of the kit in the box is 46 pounds (but the box is probably 5 pounds). Price varies, but my father paid $275 for it (most DTS's ship without the $250 spare option).

The CTS spare kit (GM #159179359) includes an unmounted 18" donut (T135/70R18) with the same bolt pattern as the G8, along with a jack and lug wrench. Weight of the kit in the box is 46 pounds (but the box is probably 5 pounds). Price varies, but my father paid $275 for it (most DTS's ship without the $250 spare option).

Interesting. I found it under part #19179359. Has anyone tried this to see if it works?

the abs will freak out if you put on a donut...might even kill someone in the rain.

Is there a provision to secure the spare? I wouldn't want it loose in the even of an accident.
If you retain the securing bolt that holds down the styrofoam compressor-sealant housing, you can rig something that will work. I just put the scissor jack on top of the spare, opened it up a touch, and screwed that securing bolt down and everything is nice and tight.

the abs will freak out if you put on a donut...might even kill someone in the rain.

That's why they tell you not to go over 50 mph with a donut on.

Anybody try the CTS donut? Sounds to me like the best compromise.

I got a nail the other day, and used a plug kit to fix it. I did forget they are kind of a pain to use on the side of the road. You've got to find the nail or hole which usually involves moving the car until the tire is in the right position. And then you've got to remove the nail before you can plug it. So I guess needle nose pliers and a flashlight are required as well.
IMO, plugging is much easier than changing a tire, and I worry that fix-a-flat may throw the tire out of balance. I agree that pliers and a good flashlight do make the job much easier.

thoughts on the tire goo getting on the tpms?

thoughts on the tire goo getting on the tpms?

TPMS hates tire goo. GM claims that the goo they ship with the G8 doesn't hurt the G8 TPMS. A couple of people on this board say GM is dead wrong.

I bought the JHP jack and spare kit, myself.

My 2008 GT has a spare, with a tire tool and jack. Looks to be factory installed, has the threaded rod coming up threw the center with a spinner nut to secure it.

Just curious as to why mine has one and it seems no one else does? This thread is a year old, did they include a spare on the later 08's? :confused:

My 2008 GT has a spare, with a tire tool and jack. Looks to be factory installed, has the threaded rod coming up threw the center with a spinner nut to secure it.

Just curious as to why mine has one and it seems no one else does? This thread is a year old, did they include a spare on the later 08's? :confused:

Did you buy yours new? Maybe the dealership added it from a CTS or something like that? I bought the JHP space saver tire and tool kit too. Fits like it should have been from the factory...

I bought it used, previous owner must have added a kit.

i put one of my stock 19z in my truck as a spare.i just need to get a little jack and t wrench from autozone or somthing

Has anyone with a GXP found a viable solution to this? I want a Donut spare to put in the trunk and a jack and lug wrench. The Goo and Air are not going to cut it for me cause I will get a flat in the rain on a dark highway mile away from anyone LOL.

Has anyone had a blow out yet and try using the sealant with success?

Seriously? There is no spare tire combo that will work with this car?
Anyone try out the CTS 18 inch spare tire?

Some people have been parting their stock wheels to others as full size spares. As far as I know the V6 could be had the same 18" wheels as the GT and came with a spare kit, so that's also an option for those with 18's. I'm yet to price the spare combo from the stealer.

I guess i should read the other 2 pages but why not go the route of the other tons of people in here and just buy a take off wheel tire from someone in here?
I parted out my 19" wheels/tires for $250 each so four people could have spares.

If it troubles you that much, $250 is nice assurance.

This is why God made Roadside Assistance! I don't want the weight, anyway!

Some people have been parting their stock wheels to others as full size spares. As far as I know the V6 could be had the same 18" wheels as the GT and came with a spare kit, so that's also an option for those with 18's. I'm yet to price the spare combo from the stealer.
The G8 V6 space saver spare tire does not fit in the front of the G8 GT (it won't clear the front brakes).

You can order from JHP in Australia a jack tool kit & 17" space saver spare tire that does fit the G8 GT.
http://www.jhp.com.au/g8partsdirect/Wheels.htm

Seriously? There is no spare tire combo that will work with this car?
Anyone try out the CTS 18 inch spare tire?

i ordered the cts kit over a month ago... parts dept. says the are back order... still waiting

I have a dozen Commodore spacesavers wasting away............

I'd rather have the tire sealant instead of a donut. It's a pain in the @$$ to use that crappy jack.