kocoach

I have a 1987 corvette with 154Kmiles and am currently using mobil one 5/30 full synthetic motor oil and it doesn't use a drop of oil nor smoke at all. A mechanic I was talking to said not to use synthetic oil in a high mileage motor, he recommended Castrol gtx high mileage oil. I'm a little confused as I thought full synthetic was good for higher mileage cars. Can somebody please enlighten me as to this matter. I live in southern calif. so the temperatures aren't that severe.

Thank You

Axial

If no problems have surfaced and you've been doing that for a while, don't change what you're doing.

I've been putting 5W/30 synthetic oil in high mileage cars for years. No problems so far.

SeeFourSix

Agreed & i do the same. There are threads like these on every forum.. do a google search and youll find more than what you want to read regarding reasoning. just keep using the Mobil 1 syn.

PLRX

The last two oil changes on Betty Boop (LT1 with 139,000 miles) I used Mobil 1 5w30 High Mileage. Believe it or not, the infamous opti spark oil seal leak stopped. I almost went insane after I saw the area dry, and no oil dripping from the crossmember.