Due oil change?

I bought a 2008 Pontiac G5 coupe with 42,000 miles on it. the question about oil change on Owner Manual says base on driving conditions, temperature, engine revolutions, not on mileage. The computer will tell you when it’s time to change oil. The dealership said to change every 3000 miles. So Oil quality are supposed to last longer than 3,000 miles. Help me with this cuz it is under warranty till 100,000.



If you change the oil more frequently than what the owner’s manual recommends it won’t void the warranty.

The problem with these oil change computer programs is they can only monitor certain parameters as you mentioned as to when the oil should be changed. What isn’t taken into account is if there’s a failure that contaminates the oil. For example if there’s internal coolant leak that’s contaminating the oil. That’s not monitored. Or if there’s a fuel leak that contaminates the oil. That’s not monitored. So if you wait until the computer tells you when to change the oil and either of things are occuring, by the time the oil is changed the engine could be trashed.


First I suggest that every 3,000 miles with a modern oil in a modern car is overkill. I would at least go to 6,000 without any concern under normal driving conditions.

As for the computer vs time/distance oil change times, I am not quite ready to go with the computer yet. Maybe by the time I need a new car.

That said, dealers do make money changing oil ?. What motive do you think they might have by suggesting more frequent oil changes?

If most of your driving is short hop, stop and go then 3k miles should be adhered to. If most of your driving involves a lot of open road extended driving then I don’t see a problem with going 5k between changes. With the latter, that’s assuming there are no engine performance problems, no problem with the crankcase ventilation system, etc.

You should ignore what that reminder is telling you. Do a search on this forum and you will find a huge number of posts related to oil sludging (generally caused by not changing the oil often enough) and what seems to be rash lately of people who now own cars with trashed engines because they relied on the reminder. Some are due to sludge, others are due to oil starved engines in which the owner never raised the hood to check the oil between changes.

What does the the Oil Life Monitor on the G5 say? The OLM indicates my 2010 Cobalt can go 9000 miles between oil changes. I’ve always used a 4k interval between oil changes. I’ve decided to do 5k changes on the Cobalt. Personally, I’m not comfortable with a longer interval. With today’s modern oils, 3k is overkill unless driving involves a lot of short trips.

Ed B.

the OLM on G5 says like 62% But thanks all replies that seems accurate information I thought I go for 5,000 miles interval oil change. Thank you all I much appreciated!!!


There was a proposal in Congress to change the recommendation to 10k for oil changes. That proposal was based solely on saving oil imports, not motor needs. Listen to the old timers like me and do 2 times a year or 5k minimum.

In 100% of cars, you MUST follow as a minimum the warranty requirements or warranty is toast.

I personally do not lose sleep if someone wants to change his oil every 3,000 miles, but for most drivers it is a waste of money. Still, in comparison to cost of a new motor, it is trivial.

Two things you can do if you want to know the truth about oil changes. Go to www.bobistheoilguy.com and read all material there.

If you really want to know when YOU need to change oil on YOUR car, at the time you choose to change the oil, send a sample to Blackstone Laboratories and let them tell you what shape it is in.

On my 2002 Sienna, with now 173,000 miles, around 15 months ago I did just that, because I was tired of all the random opinions here. I use Mobil-1 EP, and mostly do not drive in the Snow Belt. At 8800 miles, the oil was still good on all parameters, additives; contamination levels, everything. It could have gone to 10,000 miles in good shape.

So, now I change at 8,000 miles. That will not be true for a different car, or different driving pattern.

The test also tells you what shape your motor is in, which it turns out is probably much more useful than the condition of the oil. If your motor has excess bearing wear, it will tell you. If you have excess valve train wear, it tells you. If you have coolant contamination or too much dust getting by the air filter, or blow by, it tells you that, too.

My next project is to put in dino oil, and drive it 5,000 miles and have it tested, to see if those opinions that synthetic oil is just a gimmick is true or not. I do not wish to push dino oil to the same 8,000 miles.

I feel that a lot of opinions here are just guessing. I don’t think that is wrong; it’s their car and their money. The problem is when people guess, and try to convince others their guess is scientific.