Hey all,

This may sound like a REALLY stupid question, and I did do a search on the forums before this but couldnt really find a diffinitive answer. When my dad and I got our 951 the guy we bought it off of told us he was using the Mobile One Synthetic. I couldnt find the post again but I remember skimming over something that something along the lines of "dont use that for x, y, z, reasons." Any feedback?

 

alot of people don't use synthetics in our cars because it will make oil leaks much more apparent; if your car is completely up to date on maintenance items and all seals that are in contact with oil are replaced etc, your car shouldn't leak even with a synthetic oil. that being said I personally use valvoline VR 20w-50; alot of people on here seem to use that as well as castrol gtx, amsoil, and redline

 

Some will say not to start using a synthetic oil on a car that has lived a long time on dead dinosaurs because it will start to leak. I can confirm my experience with this.

If the previous owner used Mobil 1 and it does not leak, by all means continue to use it or a full synthetic from Castrol or Redline. Porsche actually recommends the Mobil 1 0w-40 for all of its cars. Use a good quality oil filter too, like mahle, purolater or the factory unit. I bought factory filters for $5.23/ea from a dealerin Atlanta a few weeks ago. Don't forget the seal ring on the drain plug either.

 

Someone posted a thread that had an oil shoot out with a grinder. Certain synthetics and blends had amazing results and I started using Valvoline durablend from that. Summertime I can do 20w50 but it was too thick once the weather started getting cold and the car seemed to bog at startup. I switched to 10w30 and it was fine. I'll definately switch back once the weather here stays above freezing.

 

What Porsche recommends for which series of cars, and what works is really open for debate. Using M1 0-40w is not good for our cars.

 

Synthetics also won't coke up th turbo's bearings as readily as regular oil when exposed to the high heat of the turbo.
Other than the leaking issue on some, I not aware of any other problems.
That being said, Mobil 1 used to be one formula. Now there seems to be several based upon change intervals and additives. I have switched to Castrol's Syntec, 5-40 for the Audi, and 5-50 for the Turbo S.

 

I just bought a quart of Redline 20W60 HD to try out. I am currently using Amsoil 20W50, I'm gonna see if it burns more or less...

 

There is a reason Porsche used Mobil 1 in their current racing applications -- it's darn good oil.

I've also had good luck with Cenpeco Racing oil in the past (before a rebuild when the engine was pretty leaky...)

 

Scrub.

 

Van do you believe that they use M1 because it's emblazoned across some of their cars or do you know they do for some other reason. Porsche used straight 50w Shell for many many years even though they had the other brand's advertising on the car. There's a reason they did this too.
Why was your engine 'pretty leaky' too? Synthetics are known for this trait as well.

 

No,it's not, Amsoil is superior to it in every independent laboratory test, Redline is also a better oil, they both beat it with no sweat, it's more than likely that they have a business relationship, doesn't mean it's better, it's more for publicity...

 

Anybody here ever use Motul?
Their racing version in the 2 liter cans (I think it's the "300M", or something).

 

There is an interesting thread on oils over in the 911 forum. A couple of good links, and some insight.

 

I'll have to look into Amsoil and Redline... I didn't know that they advertise but not use it.

About the "leaky engine" -- it had 110k miles and never had any seals replaced. They all wept oil. So I did an engine job, and other than the seals that all needed replacing, everything else was fine. Crank and rod bearing showed minimal wear. Crankshaft and camshaft were dead-nuts straight. Cylinder walls A-OK. That was with about 80 track days (4 years averaging 20 days a year).

Since the rebuild, three years ago, I've used Mobile 1, and still it consumes less than 1/2 a quart over the course of a 3 day club race -- about 350 to 400 track miles.

 

I personally haven't used Motul 3000, but I know its of a very high quality Ester based synthetic.