HkPlinker

OK, I have an 88 930 cab that , I believe has had convientional oil all it's life. I want to take advantage of the benifits of syn oil. This car has never leaked since my ownership. I know that may change. Any advice?
I should mention I am adding a Febspeed dual exhaust, 1 bar spring and a B&B intercooler, So I would like the added help of the syn oil.
thank you

Sameer

I switch between syn oil at times and have not encountered any problems

nathanUK '81 930 G50

Everybody advises it for the 930. Get as close as you can to the grade's.

srf506

Even though mine developed a leak, I'd still switch. Its so much better protection for the turbo and motor.

HkPlinker

Should I go with 0W40 or 0W50? It's a 70k mile car

ENGINEERMAN

That seems to work well.

srf506

Geez, unless its a new car I don't think I'd ever run a zero weight oil in it. 15 or even 20w-50 would be my recommendation.

the_Wolf

Mobil 1 15w50.......I've never heard of anyone running 0w50 in these, at least according to conventional wisdom, and the fact that you are in a relatively hot climate, where cold viscosity is less of a consideration. I'm sure others will chime in and may even refute this, but everyone I've ever encountered is indeed running the 15w50.............regardless of leaks, I'd make the switch.

Regards,

- John

HkPlinker

15-50 it is. I did not know the correct values, but I drive the car in 75-100 degrees outside temp. Thank you all.

PorschePhD

Swelling agents have gotten better but if the car has lived on conventional oil leave it on conventional oil. The key is change, change and change. Did I say change the oil? There is no such thing as changing too much. It cost me a small mint to change mine as much as I do, but it will do no harm, rather it helps move the acids and junk out of the motor.

Switching to Mobile 1 often will induce leaks and will cause seepage from areas that were not present before. Molecules are smaller and find their ways out. If you must change 15-50 is the key. The 0 weight oils are use for active valve trains that need that weight for the hydraulic function of the active valve train. It is a must for proper use.

vascott99

I use Mobile 1 15w50 syn and had no probs with leakage and summers here in VA are in the 90's and car did not overheat. The only thing that was overheating was me with no AC

srf506

I confirm the temp deal in the 90's here in Florida too. I did get one leak however.

Millhaus

If I may chime in in the conventional vs. synthetic debate.

What I have been told by a friend at Thyssen Krupp is that the older engines are not machined with a micro finish like the newer engines.

With micro finishing of camshafts, cylinders etc. there is more benefit gained by using synthetic oil. The molecules are finer than conventional and the benefit is gained in the tighter tolerances of the engine. This is not needed in older engines.

Also, conventional oils leave a "skim" coat on the parts and synthetics does not. This again is better for older engines. Fossil oils tend to "clot" better which is perhaps why some have experienced leaks when switching to synthetic oils. .

So should you switch? It is up to each person but there is no real benefit gained from older cars like ours to use synthetic oil. The best insurance is to change your oil OFTEN. The cost will probably be the same as if you left synthetic in longer but I personally would rather have cleaner oil in there more often. Remember that it is approx 13 quarts so you have alot of "protection" anyway.

Just FYI I run conventional Castrol 15W-40 in my 1980 930 and I change it every year or 3000 miles.

Millhaus Out

A930Rocket

I change mine after every two to three DEs. That comes out to about 750-1000 miles between oil changes. I can't see using synthetic at that rate

nathanUK '81 930 G50

The Synth is better protection for the turbocharger, much better protection. Especially when switching off the engine after using boost.
It has been said that it is not best for the actual engine, very minimal difference though.