Which weight M1 in my Porsche racecar

[sml diesel]

Disclaimer: I know virtually squat about oil chemistry etc.

Now that that's out of the way, I have a 1989 Porsche 944 S2 track car (3.0l, 16 valve, 4 cylinder, 100,000 miles) and am wondering which is the best weight Mobil 1 to use. Most of the guys I run with use 15W - 50 but I know that the modern Porsches, including the race cars all run 0W - 40.

I contacted the PCA tech and he said to use what the "manual reccomends" which is anywhere from 5W-30 to 20W-50 dino oil. There is a comment about synthetic oil comming onto the market but that's it.

I understand there is a "slight" performance advantage to going with the lighter oil but would this be worthwhile in an older engine.

BTW, I do use a little oil over the course of a weekend but most Porsches do. I change the oil and filter after every other weekend. Any advise would be most appreciated.

Thanks.

 

[buster]

I would only use Mobil 1 15w-50 in your car. *Not the Extended Performance version. Different oil.

 

[oliver88]

I have been racing a 964 cup for 4 seasons and the best UOA's I've had were with Redline 10w40. Oil was in use for approximately 6 hours. IMHO, your engine will thank you for using Redline,especially if it's hot at the races. Terry Dyson was doing my UOA interpretation and he seemed pleased.

 

[Doug Hillary]

Hi,
smi diesel - You request a M1 product recommendation. Buster is correct IMNO in suggesting M1 15w-50 but M1 Turbo Diesel Truck 5w-40 will do an excellent job too!

If you want to use other than M1 then oliver88 has it nailed!

Regards
Doug

 

[benjamming]

What oil are you using now? What are your oil temps?

 

[sml diesel]

Thanks for the comments so far guys.

I am currently using the M1 15W-50 (original version). I do not have an oil temp gauge but my water gauge has never been hot. The car does have a factory oil cooler and given it's location gets alot of air (at speed). I've also removed alot of extra parasitic equipment (a/c, heater, etc) so the cars cooling just takes care of the car if that makes sense.
I guess I should do an analysis at the next oil change and see how the numbers are as a first step.

Oliver88 - a 964 Cup?? great cars but since yours is an air/oil cooled car it's probably comparing apples to oranges. Ever run at VIR? It's my home track. Went to Mid Ohio for the first time last May. Another great track.

Keep the comments comming.

 

[oliver88]

Hi SML,

Was at VIR in February 2007 for a NASA race...going back this February as well...Going to race in 944 Cup series with my 944...The 964 cup gets many laps at Mid-Ohio as we live about an hour from the track!