My 96 Just turned 100k. I want to start using synthetic. Is it a good idea to change the type of oil on an old engine? Should I use a blened oil for the first few oil changes, then switch to a full synthetic?

 

I switched my oil half and half on one change then went to full synthetic on the next.. I like the mobil oil, not mobil1, just mobil.. Its in a white bottle with a green cap.. Its a high mileage formula and its a 10w30 which is what i have always used on my car, I feel its best for it.. But I like what mobil advertises that it keeps seals lubricated and conditioned and cleans deposits.. Try it out.. I love that stuff.. I think its one of the only high mileage formulas that come in synthetic. Its only like 2.50 each qt..

 

I use mobil 1 10w30. I have 114k on my car and when i switched i did a half and half change and then i went to four quarts synthetic and one quart regular and then to full synthetic. I do use the acdelco filter not the mobil 1.

 

i use redline 10w30 in mine..love it!

 

Mobil 1 0w40 based on the recommendations of Patman. Works good for me. I also use the Larger oil filter.

 

i've used castol syntec for quite a while now. I've always understood NOT to switch to synthetic on a 100k mile plus car do to the fact that synthetic will seem to find all of the leaks.

I have used castrol syntec and love it. I drive the **** out of the car when i do drive it, and i still have about 60lbs of oil pressure when i start it up and right about 35 at idle when the engine is hot.

 

Thanks alot. Sounds like I'll go half and half for awhile, with 10w30.

 

Royal purple 10w40 as recomended by Patmanalso.

 

I also run mobil 1 0-40 based on my own results, and those of other local F-bodies. It's good stuff.

 

Mobil 1 10W30 year round (I'd use 5W30 if I still lived in Saskatchewan).

PF35L sized filter (extended capasity and bypass-valve).

180,000 miles on the engine with no problems so far. (original opti!)

 

Mobil-1 5W-30

 

Just switch 100%.

The only isue with synthetic on a 100,000+ mile engine that has been run on dyno oil is that it tends to clean out the sludge from the engine. That means two things; One, you want to change the filter (not the oil), at 500, 1000 & 3000 miles. Two, if there was a leaky gasket somewhere that was plugged with sludge, the synthetic is likely to uncover it and it'll start leaking.

Jus so you know, I switched to Amsoil in everything I own several years ago, and I only change my oil once a year now. I still have to change the filter every 3000 miles of course, but I'm still saving a bundle.

On your engine, because of it's age, I'm going to say that a nice 10-40 synthetic would be good for you. Don't go to a 20-50... too thick.