Pontiac G8 Forum banner
1 - 20 of 48 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter · #1 ·
In Winter i am using 5W - 30 SAE, what oil is best for summer?

Our oil pans are larger than normal cars, do we still change oil every 5,000 KM? I read something about only around 10,000 KM. But if our engines use more oil than normal oil pans, it would make sense that we too change oil every 5,000 KM.

Anyone know?
 

·
Registered
Joined
·
228 Posts
I believe the G8 only calls out for 5w30. Oil change intervals depend on some variables but with synthetic you are safe for 5,000 plus miles in most cases.
 

·
Registered
Joined
·
1,459 Posts
I watch the oil life indicator but typically change mine at 10k mile increments with full synthetic.
 

·
Registered
Joined
·
5,210 Posts
Definitely stay 5w30 year round. I think I've read a couple people do 0w30 but I'd stay with the 5w. I plan on doing mine between 6 and 7k. People do wait until the o.l.m. kicks on and its been kinda debated about what mileage to change it at . That's why I kinda figured I'd be kinda in between 5 and 10.
 

·
Premium Member
Joined
·
7,446 Posts
V6 Engine Tech (LY7) > Type of Oil and when to change Oil (cough, cough) The car calls for 7.1 quarts of oil. I have used Castrol 5W-30 regular blend every since the second oil change. I usually change it when the OLM (oil life monitor) gets down around 25%, not sure about the exact mileage.
 

·
V6 power
Joined
·
139 Posts
fully synthetic Valvoline every 6500 miles , my car seams to like it :)
 

·
OGOC Member
Joined
·
2,642 Posts
I use Castrol edge with syntec full synthetic every 10,000 kms.
 

·
Registered
Joined
·
1,210 Posts
I would change it sooner rather than later on these engines. GM cut back oil life to 5k miles on the direct injected 3.6 due to timing chain problems. The port injected motor is a little more forgiving but not much.
 

·
Registered
Joined
·
444 Posts
Mobil 1 Advanced Full Synthetic with a Quart of Lucas Oil is what I use all around. I've noted because I let the oil life monitor go to full and tell me I need an oil change. When I changed out the oil I could still see through it when it drained and this was roughly about 9k miles between changes. Normally I do 5k Intervals though to time it with tire rotations.
 

·
Registered
Joined
·
107 Posts
Speaking with GM Techs, they all said that becasue of the Timing Chain issue that 5k should be the limit. And if you go over to monitor your oil level.
I use Mobile 1 Synthetic. I bought my car used... and there wasn't a lot of history on oil changes before me.. probably was part of my timing chains going out. Car had 72k on it when I bought it and have run Synthetic since then and changed every 5k miles.
 

·
Registered
Joined
·
107 Posts
I just had to get my Timing Chains replaced. The GM Dealer told me that this issue is largely caused by oil that has been left too long in the engine or was constantly running low and not refilled. I know the above conditions weren't on my part as I replaced every 5k..and always check to make sure it's at the right level ever since I bought it.
The GM Tech's told me that they wouldn't go past 5k... That OLM has no way of checking the viscosoty of the oil... it goes on the mileage that the engineers deem to be the threashold. It's not that much of a deal for me to change it at 5k for peace of mind for my car.
Just my .02...
 

·
Registered
Joined
·
1,793 Posts
.. it goes on the mileage that the engineers deem to be the threashold. .
Just my .02...
Do you know for a fact that it goes off of mileage?.... what does it have a random number generator and then mix it up for each oil change?.... I dont think you are correct on this....... I really dont.....

the timing chain thing sounds interesting also but think its due to more of the crappy setup the g8 has and if you fix that then I really doubt the oil going up to its full life will effect that.....
 

·
Registered
Joined
·
1,793 Posts
The GM Dealer told me .....The GM Tech's told me that they wouldn't go past 5k...
first mistake,..... you listen to the dealer!!!! 2nd mistake..... going over 5000 miles is no issue and will not cause timing chain failures.... other things cause that,.... running to 8000 miles will not cause any more timing chain failures than running to 5000.....

and I would really like to know where you got your info on GM oil life change system..... seems all the algorithms and calculations they do on this system seems a bit complicated when they could just add and subtract from odometer,.... maybe I should tell them and we could save tons of money on systems like this.... :)
 

·
Registered
Joined
·
107 Posts
Well guys... I'm not going to get into a pissing match over this. Change the oil in your car as you feel. With that said.... here is the low down on algorithm vs direct measurement...
Algorithm-based oil indicators measure lots of factors and then plug the resulting numbers into a formula. Based on the answer to this complex, ongoing math problem, the indicator display will tell you whether the oil is OK, is close to requiring replacement or needs replacing immediately.

Interestingly, with these types of indicators, there are no sensors to detect the quality of the oil itself. Instead they combine data on how many miles you've driven, the temperature variations during that time and data about how much work the engine has performed. Typically, the indicator (monitoring system) will receive such data from the powertrain control module, or PCM, which is the main on-board computer. Engineers have figured out a fairly accurate and reliable way to calculate the remaining oil life this way, without having to actually sample the oil.

Direct measurement oil life indicators measure the condition of the oil -- the opposite approach to the system described above. This method uses sensors to sample the oil and determine its remaining life based on any of the following:
•Conductivity -- how easily electric current passes through the oil (typically, the lower the electrical resistance, the more contaminants are in the oil)
•Mechanical properties -- piezoelectric sensors can tell how thick the oil is by the force feedback it gives when sloshing around
•Soot concentration -- dirty oil's days are definitely numbered
•Presence of water -- water is an impurity in oil, since it hampers the oil's effectiveness and can corrode metal surfaces

Different oil monitoring system manufacturers may use a combination of these measurement techniques. Typically, the information will display as a digital readout on the vehicle's instrument cluster. The display can feature a green, yellow or red-style status bar, with red indicating the "change oil now" zone; it could be a percentage, displaying a text message, something like "40 Percent Oil Life Remaining," or it might just be a light or a message that just comes on automatically when it's time for an oil change.


Now with THAT said.... I just don't trust what has been established in a lab...not when it comes to my car.
The people I have been talking with this are GM Techs as well as other Mechanics. 2 different Techs have told me that none of their cars go over 5k miles without an oil change. I tend to trust the guys that do this for a living. One Tech, a GM Tech, told me that if GM were standing here that he would have to say trust the OLM system. But he himself doesn't let any of his cars go past 5k miles on oil changes...and he runs Synthetic.
I'm not claiming to know it all on this. Just that I talk with these guys and as stated... I'll trust them that do this for a living before I trust a computer measurement system that can't test the viscosity of my oil.
 

·
Registered
Joined
·
9 Posts
I'm old school with oil change intervals... 3,000 miles or 3 months. I believe it is up to personal preference on what type of oil to use when considering synthetic or other. Of course the type also depends on warranty conditions too.
 
1 - 20 of 48 Posts
Top