[fast68]

got a 91 s10 with 4.3L in it that has recently rolled over to 200k miles. always runs perfect, strong, and totally reliable..
im considering swapping to synthetic oil...not full synthetic... but maybe about half and half...

is this a good idea? why or why not?

or should i just leave well enough alone?

thanks

[Vince Black]

I usually suggest my customers change over to full synthetic at about 50k (give or take a few k). I would say in your case if you take care of it well enough to get it over 200k with conventional, don't fix it. It sounds like it "ain't" broke.

I also wanted to add that I am a mechanic and the original owner of a 92 Plymouth Laser 1.8L car (Mitsubishi Eclipse). Yes, as silly as that sounds, it is absolutely true, but with 292,xxx on the odometer and not a single major issue, I still use conventional. It was the first car I ever owned, and I can recount exactly every part I have ever put into it, about $1000 worth. Not too shabby IMO.

[302 Z28]

You can switch to synthetic any time you wish, but I agree with the above comment. If you have that many miles on conventional oil why switch at this point?

Vince

[cobalt327]

Originally Posted by fast68

got a 91 s10 with 4.3L in it that has recently rolled over to 200k miles. always runs perfect, strong, and totally reliable..
im considering swapping to synthetic oil...not full synthetic... but maybe about half and half...

is this a good idea? why or why not?

or should i just leave well enough alone?

thanks

I wouldn't do it, personally. Far more important to keep up a good oil/filter change schedule than to (at this late date) change to a synthetic or semi-synthetic oil, IMHO.

FWIW- there are countless cases of high(er) mileage vehicles suddenly springing oil leaks when changed over to synthetic oil.

[Ford Junkie]

Originally Posted by Vince Black

I usually suggest my customers change over to full synthetic at about 50k (give or take a few k). I would say in your case if you take care of it well enough to get it over 200k with conventional, don't fix it. It sounds like it "ain't" broke.

X4 on that.

The wife is driving a '05 hemi dodge ram w/235,000 miles on it and it still uses 1 quart during a 5,000 mile change interval. It did it brand new and still does the same thing now. I ain't changing nothing!!!!!