http://www.youtube.com/watch?v=yj3MpnZgXRI&feature=grec_index

I stumbled accross that video just a few moments ago. After the first half, I was quite surprised at how well DoD worked on that GT, getting him 30 MPG highway.

What puzzled me more is that without DoD, he was getting 27 MPG highway.

I have NEVER seen more than 24 MPG on my V6, even on a 365 mile highway trip to Canada. Is there some kind of joke here?

In town, I've seen as low as 13.5. Sure, my driving isn't the most fuel efficient, but when I try I can't even get over 18 in the city. That's even after resetting my mileage and fuel economy and having a fresh tank of gas.

Are the other V6 drivers experiencing this? or am I doing something very wrong?

http://www.youtube.com/watch?v=yj3MpnZgXRI&feature=grec_index

I stumbled accross that video just a few moments ago. After the first half, I was quite surprised at how well DoD worked on that GT, getting him 30 MPG highway.

What puzzled me more is that without DoD, he was getting 27 MPG highway.

I have NEVER seen more than 24 MPG on my V6, even on a 365 mile highway trip to Canada. Is there some kind of joke here?

In town, I've seen as low as 13.5. Sure, my driving isn't the most fuel efficient, but when I try I can't even get over 18 in the city. That's even after resetting my mileage and fuel economy and having a fresh tank of gas.

Are the other V6 drivers experiencing this? or am I doing something very wrong?

I get an average of 22-23 mpg, mostly city / rural highways, so not really a highway.

Do you push it to the floor off the line, or are you slow about it?

Off lights it is usually wot, so not really helping the case.

Sometimes I do that, most of the time I don't. What can cause such horrible fuel economy? I might as well have bought the V8.

They are so close it's not a determining reason to buy either.

No matter what I do I have not been able to get over 22.4MPG, long distance hwy driving in a V6, (with air conditioning off) and conbined with local, stop and go driving, 19.8MPG. Disappointing to say the least.

Having owned 3 different G8's now (White Hot V6/Liquid Red GT/MSM GT - heavily modded) I can honestly say that the difference in fuel economy between the V6 and the GT is next to nothing. The V6 'feels' bogged down and therefore you tend to ride the throttle harder whereas you can feel the response from the V8 meaning you are on the throttle less off the line. I remember I used to almost WOT off the line in the V6 but I could feather it in the V8 and get along just fine.

Also, even with the modded GT (list in sig) I get 23-24 MPG on the hwy (mind you city is like 12ish), just as good if not better than I ever got in the V6. My DoD is long gone as well. This is one of the reasons that spurred me to sell my V6 and search out a GT... Fuel economy is really not a valid reason not to get a GT, and I'm literally paying 50 bucks more a month now than I was for my V6. I couldn't justify spending what I was knowing that for just a little more I could have this many ponies at my disposal (about 560 now).

I've had both the v6 and now a GT. Traded for GT once pontiac was killed. My gas mileage was/is this in same daytime temperature:

Combined to and from Work: V6 - 24.5 GT - 23
Highway @ 75mph on same trek V6 - 25.5 GT- 25

Your fuel mileage may vary.

http://i21.photobucket.com/albums/b271/29whips/gas.jpg

About a year ago, I drove across three states and got a 26 MPG average with an averag speed of 70 using the cruise control almost all of the time. best was 26.5 at 75 MPH average.

On my last trip up north, I only got around 19 MPG average. Difference between the two trips, tires and temp. I don't think the tires had that much to do with it but the temp was a whole lot colder last week when I took my north bound trip and the tire pressures were down about 3 psi of what they would normally run at higher temps.

Would a CAI help in improving gas mileage somewhat, or am I better off keeping the V6 stock intake as is? MPG seems to vary widely with those posting here. Does anyone think it would be worth while taking it in to the dealership for a check/evaluation?

I'm very pleased with the fuel economy on mine. It seems to do best on 89 AKI fuel.

I consistently get 28-29 ish driving between our two residences - this involves crossing over the Boston mountains which separate our two homes. My wife's Torrent GXP that has the same HF V6 engine seems to get about 1 mpg less even though it has an extra gear in the transmission.

To put that in comparison, my '04 GTO got about 21 on the same route, my Xj12 gets about 16, and the Xj8 and Solstice can both top 30.

I get about 18 ish in town - depending on ambient temp and how many cold starts I have to make.

My last highway run (3'ish hours non-stop) I got 27 mpg. That's cruising at about 65 on winter tires with an ambient temperature close to the freezing mark. I've gotten close to 29 in warmer weather riding on the RS-A's.

Mine's a bit of a pig in the city. Generally 15-17.

Speed plays a big role. The faster you go the more wind resistance you face and the faster your engine turns. I've found between 60 and 67 mph seems to be the sweet spot.

The only way you will see 30 is resetting it while moving already, and sitting around 90-100km or 55-60mph, little to no traffic and no lights or stops. I tried it on the way to work and got 29.9 average over a 10km stretch of road with no lights or traffic.

What do you guys use for gas? (brands)

I typically use Shell because if I use anything else I get 2-3 MPG LESS than the already terrible results that I am getting.

Is something wrong with my car, my foot, or me for thinking I should get better fuel economy?

What do you guys use for gas? (brands)

I typically use Shell because if I use anything else I get 2-3 MPG LESS than the already terrible results that I am getting.

Is something wrong with my car, my foot, or me for thinking I should get better fuel economy?
I use BP Silver 89, does best with it. my wife got 29 going across PA from border to border. gennerally i get 24-26 highway,not the lgest foot here .

If I was really concerned with getting great gas mileage. I would of bought a Prius. I'm heavy on the foot so I will never see good mileage to cheer about.

If I was really concerned with getting great gas mileage. I would of bought a Prius.

^^^This.:judge:

We went from a Mitsu Lancer that got 25 city/34 hwy to a the G8 that gets around 25-26 hwy at best. Didn't buy the car for the mileage.

If I was really concerned with getting great gas mileage. I would of bought a Prius. I'm heavy on the foot so I will never see good mileage to cheer about.

+1... add that too the fact with the Solo's on I like to give her a little goose every now & then it gets some people's attention the way she sounds...

I haven't reset my milage counter in 14K miles (have 15K total). My overall average speed reads 42 and my mpg is 19.4. The car is an M6 GXP with a VCM OTR and tuning. DFCO and CFCO are both off. It sees 5-6 pulls to XXX every day on the way to the office. Overall I'm ecstatic with the performance, value and MPG of this car!

... now I just need to stay off the black ice until it goes in for the winter.

I average 19+ MPG in my daily driving (combined city/highway).

on all highway drive it reached up of 28MPG and this with 15min doing >125 MPH

...and this with 15min doing >160 MPH

Nice! :eek2:

Nice! :eek2:

LOLLLLLs... my bad , 15min dong > 125mph (original post corrected)
poor math transforming km/hr to mph :))

There are many factors to consider when it comes to gas mileage, separately, all are somewhat negligible. However, as a whole, they tend to squeeze an extra gallon here or there. Things such as: 1. Grade of gasoline. 2. Quality of gasoline. 3. Proper inflation of tires. 4. Weight of vehicle 5. Elevation 6. Outside temperature. 7. Driving habits
8. Condition of vehicle 9. Oil (so they say) 10. A/C on or off 11. Position of windows. 12. And the list goes on and on eternally :eek:. Me personally, I just get in the darn thing, drive, and try not to over analyze the situation. Sure, I hoover around the speed limit and try not to drive like those Fast and Furious individuals. I average about 20city and 25hwy. Have been as high as 25city and 33 (I believe) hwy.

LOLLLLLs... my bad , 15min dong > 125mph (original post corrected)
poor math transforming km/hr to mph :))


lol, still, nice at that speed for sustained travel! :)

16-18 city, 22-24 hwy

averaging 19 now thats its winter. would average between 21-22 during the summer with highway in the 27-29 MPG range

I get what people say, "I didn't buy the G8 for fuel economy", that was the same story on the RX8 board, but I love it that I have tons of power on demand and for a heavy girl I still can hit 24mpg highway.

I can't wait to tune her and see (from what I hear) the better fuel economy numbers.

Highway driving with A/C+cruise+70=28.5.29.5 depends on terrain and/or wind.
I've calculated it using the DIC and fill-ups both.
Around town 22-25 but I'm very light-footed.

Around town 22-25 but I'm very light-footed.


you must have a feather foot

Just drove to Texas and back for the holidays. 2500 miles total. Overall average was about 24. Best being 25.5. Got better millage once I left Ca and fille dup over in free America with the cheapier gas. .40 a gallon less in Az, N.M. and Tx AND I got better milage. ;).

Still alot better than 7 MPG in my old truck. But not as much fun, truck had a blown 383 stroker pushing 600 HP. :) And it was my DD until I got my bike. ;)

averaging 19 now thats its winter. would average between 21-22 during the summer with highway in the 27-29 MPG range

Mine is about the same. I did get 30.7 Highway MPG for 100 miles during a trip to Nashville last summer travelling at 70MPH average. Usually, though, its around 28-29. The pure city averages 18-19 or so.
The latest from the DIC is 43.2MPH 22.6MPG. Yeah, the mileage difference is pretty slim from the V8.

Dragging up an old thread, I had to post this.

I just came back from a little road trip from Cali to Texas. One leg of the trip in Texas at nite from El Paso to Fort Stockton 256miles I got 30.22mpg doing it long hand. Can't remember the adv speed, but TX night time speed is 65mph we was doing between 65-75mph. Now this was with the AC on, three people, a trunk full of stuff, and the lowest grade of gas. My wife drove some of the time so I'm not sure if there is some downhill action in there.

I still skeptical about all these high 20s MPGs. I do not get near those numbers with a Stock car, cruise control on and at the speed limit. The best I ever had was 23 MPG and was doing 5 MPH less than the poster limit and avoided to stay sitting idle (all Hwy Miles).

I bought my car used, how do I know if is been tampered the PCM with a different tune? The DoD/AFM does works according to the DIC in Engineering Mode.

I get on average around 20 mpg 50/50 city/highway stock. If I beat on it alot I usually get around 17. Best I have got at 80-85 with AC is 24, going 60 without ac 30.5. Not bad for 361 ponies.

Math don't lie. I get better numbers doing it long hand than the DIC.

I still skeptical about all these high 20s MPGs. I do not get near those numbers with a Stock car, cruise control on and at the speed limit. The best I ever had was 23 MPG and was doing 5 MPH less than the poster limit and avoided to stay sitting idle (all Hwy Miles).

I bought my car used, how do I know if is been tampered the PCM with a different tune? The DoD/AFM does works according to the DIC in Engineering Mode.


im with you on this

I did take the car on a longer drive, reset everything and was taking it easy but not being a gradma and for the first time I seen 24mpg. I would not consider this to be normal driving, this would be strictly highway.

I do stop and go and I MEAN stop and go, and my car never says more then 14.something.
I think some people's version of city driving is different then others.

When you see around 75 MPH as an average and 22.3 MPG as the maximum and bounce on what people report some does not not jive.

Used High and Low grade, got the same Fuel Mileage.

When you see around 75 MPH as an average and 22.3 MPG as the maximum and bounce on what people report some does not not jive.

Used High and Low grade, got the same Fuel Mileage.


on the way home I got 48mpg :drink:

Make sure you are cleaning your air filters, throttle bodies and MAF sensor. All of these can be done in an hour or so.

If you feel your car sort of shaking a little when stopped at lights, stop signs, etc it could easily be your MAF or throttle body gummed up.

Once clean you will notice a sharper response and better fuel economy for sure.

on the way home I got 48mpg :drink:

That is weird!


Make sure you are cleaning your air filters, throttle bodies and MAF sensor. All of these can be done in an hour or so.

If you feel your car sort of shaking a little when stopped at lights, stop signs, etc it could easily be your MAF or throttle body gummed up.

Once clean you will notice a sharper response and better fuel economy for sure.

As far that... My MAF is clean as has a pretty new K&N drop in filter. Just cleaned it the MAF few days ago and still getting the same MPGs. I am very meticulous when it comes to things of that nature. I used to be a CH47 Flight Engineer and all the time I conduct Fuel Consumption Checks (even when I flew over water from Oahu to Hawaii on a UH-1H and AH-1F). Is part of the Health Indication of an aircraft engine. Once you establish a baseline you know if your engine is degrading by the power output and the fuel consumption. I have an 03 Impala that gives the same MPGs as new and is over 135,000 miles. So I know is running fine.

Just the G8 seems not to be (IMHO) to the fuel economy people claims. Is closer to what the Door Sticker states (give and take 1 or 2 MPGs on the low side).

http://www.youtube.com/watch?v=yj3MpnZgXRI&feature=grec_index

I stumbled accross that video just a few moments ago. After the first half, I was quite surprised at how well DoD worked on that GT, getting him 30 MPG highway.

What puzzled me more is that without DoD, he was getting 27 MPG highway.

I have NEVER seen more than 24 MPG on my V6, even on a 365 mile highway trip to Canada. Is there some kind of joke here?

In town, I've seen as low as 13.5. Sure, my driving isn't the most fuel efficient, but when I try I can't even get over 18 in the city. That's even after resetting my mileage and fuel economy and having a fresh tank of gas.

Are the other V6 drivers experiencing this? or am I doing something very wrong?

This is bizarre. I've gotten a high of 26.1mpg on my GXP.

I don't drive in heavy stop and go traffic everyday, maybe once a week, but I drive 5 miles through city and then another 8 on the highway. I usually take off faster than any other car at the lights and hammer down when merging on the highway and I have never had worse that 18mpg on the DIC. People that are getting 14-16, are you idling a lot or do a lot of stop and go traffic jams? I think I would have to try hard to get down to 14mpg.

stop & go city i get about 16. highway i found 55-60mph at 1500~rpm is the sweet spot, and setting the cruise here i've gotten 30-35 avg on long trips. regular highway driving 65-75 mph 2000~ rpm i get between 24-28

stop & go city i get about 16.

This is what I get with a Cai and exhaust. No tune.

Sent from my EVO 3D

I get an average of 25mpg.

I don't driving in heavy stop and go traffic everyday, maybe once a week, but I drive 5 miles through city and then another 8 on the highway. I usually take off faster than any other car at the lights and hammer down when merging on the highway and I have never had worse that 18mpg on the DIC. People that are getting 14-16, are you idling a lot or do a lot of stop and go traffic jams? I think I would have to try hard to get down to 14mpg.


my commute to work is 2.2 miles, the speed limit on that road is 40.
There has to be 8-9 lights between here and there, add in people turning on and off the road and its pretty much as stop and go as you can get.
Then I might hop in the car to estimate or pick up parts- same conditions.
Now when I get it on a open road im trying to up the mileage from all that stop and go.

The result: DIC says 14. all the time.

i remembered what I got 20+mpg, my average speed was close to 50mph

today I looked and my economy is 14.8, average speed was like 27 or 28

i remembered what I got 20+mpg, my average speed was close to 50mph

today I looked and my economy is 14.8, average speed was like 27 or 28

the killer for mileage in this car is stop and start driving. I originally got 15-16 mpg when there was significant local stop and start driving in the mix. On a highway trip at 75mph it was getting 23. recently as the mileage on the car exceeded 30K, I started to see an improvement in mileage...18 in my local mix and a high of 27 on the highway. Perhaps the engine was so tight new that it is just now getting fully broker in.

I do not doubt the 30+ mpg reported by those with cruise control locked at 60 mph...but that is an unrealistic speed for most people for any distance. YOu have to go faster on the highway, and on local streets the tickets you would get would kill your license. 60 doesnt just do it in most situations

I do not doubt the 30+ mpg reported by those with cruise control locked at 60 mph...but that is an unrealistic speed for most people for any distance. YOu have to go faster on the highway, and on local streets the tickets you would get would kill your license. 60 doesnt just do it in most situations

the 55-60mph trips I mentioned were at like 2am with no traffic and I was not in a rush to get home.

I tested mine driving to work only. Average speed 24.6 mph, with 18.4 mpg. Its about 5 miles each way. Mind you this is only city driving, no interstate at all.

3.4 miles to work in tampa fl, traffic gets me about 15.6 mpg if i bite my tonugue and not pass ANYONE, but on hwy i have seen it start climbing past the 21mpg, no worries, i have the bike to give me the 40mpg..

3.4 miles to work in tampa fl, traffic gets me about 15.6 mpg if i bite my tonugue and not pass ANYONE, but on hwy i have seen it start climbing past the 21mpg, no worries, i have the bike to give me the 40mpg..


I only saw 2 G8 while I was in FL last Jun. A red one in a parking lot in Tampa and another one (look like orange to me) leaving McDill AFB in Tampa.

Other than that I was pretty alone driving between Tampa and Orlando.

There are a few, i have seen a nicely modded blue one and a silver one, both one westshore blvd.

Don't forget the GT's have a 6th gear


my dad is getting around 22, majority highway with some traffic. he would get 19 out of the gto on the same trip. i got 22 through the city when i was short shifting a lot with the tapshift

my commute to work is 2.2 miles, the speed limit on that road is 40.
There has to be 8-9 lights between here and there, add in people turning on and off the road and its pretty much as stop and go as you can get.
Then I might hop in the car to estimate or pick up parts- same conditions.
Now when I get it on a open road im trying to up the mileage from all that stop and go.

The result: DIC says 14. all the time.

I'm pretty much in the same boat as you. 9 mile commute each way, speed limit ranges from 25 (neighborhood) to 55 (main road) to 75 (highway) back down to 40 (main road), probably an equal distance on each and only the highway doesn't have stop lights or stop signs. DIC says average speed is high 20's though my economy is a little higher like 15-16. Lower than I expected, but not horrible.

And another strange thing, when I had my Cobalt SS on the same exact commute, my average speed according to the DIC was AT LEAST 5-10 MPH faster than the G8. That one I can't figure out.

My 6er gets an average of 21-22 MPG and its about 50-60% highway. All highway cruisin at 75-80 I usually get 25-26. If I am granny driving @ 65 I can get up to 28-30.

I'm at around 14.8 for city driving and 23-25 highway in my v6, just put a KN CAI yesterday so I'll see what that does for my highway mileage.

Its crazy how some people's milage vary's so much. I know its all down to driving habits, car mechanical issues, weather etc. but I am a very aggressive driver and manage to do rather well in the milage department. I drive 75-80 always on the highway and agressive off the line in the city and average 21-22. The thing that may help me is i rocket off the line and then basially coast until I have to slow or stop rather than speeding up slower and being on the accelerator 75% more in duration. This works for me.

Its crazy how some people's milage vary's so much. I know its all down to driving habits, car mechanical issues, weather etc. but I am a very aggressive driver and manage to do rather well in the milage department. I drive 75-80 always on the highway and agressive off the line in the city and average 21-22. The thing that may help me is i rocket off the line and then basially coast until I have to slow or stop rather than speeding up slower and being on the accelerator 75% more in duration. This works for me.


what is your average MPH?

what is your average MPH?

I want to say its typically in the mid to upper 20's

Intersting how your mileage is so much better than mine.

I have about the same driving habits (75-80 on hwy) and get around 23 +/- and in the city 18 or 19.