Hi,
My 04 GT2 is 221,000 miles young. The engine is strong, never been abused, raced, or anything like that. I have a minor pan gasket leak, I lose a quart about every 3000 miles. The only real "issue" with this car (unrelated at that) is a valve in the fuel line which allows fuel to drain back to the tank when left for a period of time. I have to prime it a couple times before starting.
My question is, would there be any benefit to switching to 10w30? I know of many GM owners who go from 5w30 to 10w30 as their engine ages, Ive known a few who go to straight 30W. Its had 5w30 its whole life, should I mess with success?
Thanks.