I have a GTA with a 350 with 47,000 miles on it and want to start putting synthetic oil in it( Mobil 1 of course) and am worried about the potential problem of having my engine leak oil badly since ive read a lot of people posts about that. Is there any type of additive i can use or do u even think ill have that problem with an engine that only has 50,000 miles?

 

I run Moble One in mine with no problems. Using 5W-30. Allen

 

I started running synthetic in a 1969 Chevelle with 130,000 miles. No problem.

Same on a 1974 air cooled VW.

 

if there is a leaky gasket, syn oil will make it's way out more then dino oil

the plus to syn oil is it's great for 15-20K miles (like mobil 1, ams, redline, etc.)

i've ran mobil1 in my old truck for like 5 years without changing it, i did use a good fram HP filter

it was spotless inside when i opened it up when i did the intake

on my TA i go every few years changing it, it's spotless inside too

her 90 V6 FB, same thing

i used to change it every 2k, but that was a waste since it's made for long term use.

i prefer mobil one, cause you can usually find it everywhere.

i've heard you can't mix syn oils, how true that is i dunno

what i did do first was use a Gunk engine flush to clean the motor out, never hurts to do that.

 

I run M1 synthetic in my 88 IROC, and it has about 160k miles on it. Doesn't leak a single drop. I currently have the M1 T&SUV oil in it, and a good K&N 3002 filter.

 

Don nailed it. If you have a leak, the synthetic will find it. If the leak is from a seal, the synthetic will tend to clean away any sludge and varnish that may be keeping the oil from leaking past the seal. However, if the seal is not physically damaged but is only hardened, the synthetic CAN help soften the seal elastomer and eventually improve the seal. I had this happen on a Caprice wagon I owned, and the initial RMS leakage eventually stopped on its own. Unfortunately, in my case, the timing cover seal did not stop dripping, but that was an easy fix. The engine had about 120K on it when I changed to M1, and I contined to drive it until it had about 180K on it. Other than the seal, a couple belts, and maybe soem maintnenace items, I never had any problems - other than the fact that it was a 305 Q-Jet dog in a heavy car.