ok ive got a cpl simple questions, one simple one less but still pretty simple. first question is i just put mobil 1 synthetic in my car (have been for awhile now but its mostly been in shops) anyway the last time i put it in was just over 3 months ago.. barely put 100 miles on it since then. just curious as to what the life of synthetic oil is as far as how long it can be left before it has to be changed even though its not being used. and the other question, whats the best oil out for an LT1 with around 140k on the clock? i remember there was a post awhile back but i couldnt find it.. and i remmeber it was something like 0-30(german castrol?) is that safe for a motor that old?

 

Oil Schmoil: Just use some good dino oil and filter and change the oil when it gets dirty. On worn engines the tolerances are greater and I'd advise going with a little heavier viscosity e.g. 10W-30/40. I personally would be a bit hesitant about using a super slick, thin oil, on an older engine. JMHO

You asked.

 

The normal life expectancy of Mobil 1 exceeds 16,000 miles. So 3 months is nada! I would also suggest a slightly thicker oil on an engine with 140,000 miles, at least an (X)W40.

 

i always run 10-w30/40 (40 for summer) but i just remembered that post awhile back where the guy was showing very little wear on the motor with that castrol 0w30 *shrug* but anyway main question looks to be answered.. the car should be fine even with the 3 month old oil? with next to no miles...

 

M1 10w-30 is VERY thin the 0w-30 German Castrol is much thicker. If you want to use M1 just use 0w-40 or 5w-40, nothing wrong with a dino oil either.

 

I have a few leaks now that I started using synthetic, I tried fixing the Intake leak thinking that was the main one, but it wasn't. Do you guys think that my leaks will calm down if I switch back to something not synthetic? The leaks started maybe 3 weeks after I put in the synthetic.