sm

Just wondering what motor oil you guys are using. My 86 951 has 136k on it and the PO never used synthetics. What brand and what weight should I go with?

Thanks,
S

IanM

I use Mobil 1 fully-synthetic exclusively in my car. I know that other synthetics like Motul are very good, so pick whatever you like. But I'd definitely use synthetic with a turbo. Extreme heat from your turbo doesn't break down synthetics like it does conventional oil. Mobil 1 comes with either a red label or a green label, I use the red label. I think it's 15W-40.

sm

Does anyone use Non-synthetics? I'm trying to get as many opinions as possible...
Thanks,
sm

Hans

I use full synthetic 15W40.
Have a look at this http://www.pelicanparts.com/techarti...thetic_faq.htm
and this http://www.pelicanparts.com/techarti...il_article.htm
for more info

Take care

adrial

I use non-synthetic..
I've read time and time again that synthetics are unecesary as long as you change the oil every 3k and allow the engine to cool down (idle for 30secs after driving...more if after hard driving).
Now, my only reason for not using synthetic is leaks. I fear them.
I've had the car for 4 months, or about 2,000 miles..There is one minor seal ("rear cork seal" according to my mechanic) that is leaking a tiny tiny bit right now...once I deal with that I'm gonna change over to synthetic and hope for no leaks..

So basically, the only reason to not use synthetic is leaks..Some people have switched to synthetic, had leaks, switched back and then had them dissapear again...

--Adrial

ninefiveone

If the motor has been on dino oil for awhile now, there's a chance that synthetics will free up sludge that was preventing leaks. So the two downsides to synthetics are that you may see leaks and it's more expensive.

The upside is that it won't cook at the high temps the turbo sees and that's extremely important with these cars. Mobil1 15W50 seems to be a popular choice with 951's. That's what I use as well.

I know of people using cheap dino oil because they burn so much of it at WOT but they use it with full knowledge that it's not dealing with the real problem.

Basically, you should go synthetic but if you go dino, change often often often.

-Hugh

booster

I use synthetic now but I am thinking of going back to dino, I drive the car only about twice a week. I use Rotella in my other cars and it is some great stuff, most big rig truckers use Rotella and they rackup many thousands of miles between oil changes on those BIG diesel engines, this oil is also excellent for gas engines.

turbocarrera.

I've heard talk about the breakdown temperatures of synthetic beings much higher than dino oil, the fact that it lasts longer, that it might cause leaks in an older engine that has some sludge buildup and so forth.

The only thing I'm concerned about is having the detergents of a synthetic dislodge some crud in my old 3.0 turbo and having said crud block an oil passage - sounds like this is VERY possible when going from a dino to a synthetic in a higher mileage engine.

Is there a way do change the oil, maybe something else as well, that could prevent this from happening? I really want to start using sythetics but I won't if there's any chance of blocking an oil passage after the switch.

adrial

Well...this is just an idea...but if you mix a synthetic oil and a nonsynthetic oil (out of engine), what happens? Do they mix?
If so you could start rationing in the synthetic in 500mile intervals...thus only breaking up the sludge only so much..it might work but if it were my engine I'd stick with dino oil.
If your 930 is stock, then why fuss? Back when the 930 was designed Porsche designed the engine for use with much lower quality oil that what we use today, even dino oils.
If you use a good quality dino oil I think you're all set...