Originally Posted by ironbender
How many miles for a 4 cyl doing almost exclusively highway miles?
Vehicle will have 5w20 synthetic.


Oil analysis will tell you what is good. The rest is just guessing..

But with good filters and oil, I wouldn't be afraid to go 10,000 miles.

Originally Posted by captain seafire
I replace valve cover gaskets every 50K, if they don't need them sooner...