ilko

I'm taking my car to Lime Rock at the end of the month for a DE event with PDA. I'm currently running 5W-30 oil and it looks like the high temp for the day will be around 50F. Am I OK with this set up, or should I change the oil? This is for a 91 Carrera 4. Thanks!

Big6Dad

ltc

I would have thought that 15W-50 would be fine at that temperature, but 5W-40 or 0W-40 is also an approved viscosity isn't it?

Yes, I know, another oil viscosity rennlist discussion...time to hide in the bunker and wait for it ot end.

ilko

I didn't know it was discussed so much. Maybe one of the mods can create a sticky at the top and then everybody will have it as a reference.

Sean F

Oil is overrated. I'm going to use corn syrup this year.

ltc

Sorry, it's a bit of an inside joke. Oil viscosity, specifically 0W-40 being recommended by Porsche for (nearly) all it's engines, ends up turning into somewhat of a jihad.

I've run 15W-50 at LRP in March, it's a bit 'thick' during crank but once you're up to temp and running on track, it's fine.
FWIW, I run 15W-40W in my wife's Excursion Powerstroke this time of year and it's OK.

bgiere

https://www.pca.org/tech/tech_qa_question.asp?id={D7EC45C3-9BA1-4C61-B220-8BA6874F1C20}

amfp

5-30W is too thin and should not be used even on the street. I would change to 0-40 or 5-40 before the DE.

ltc

As a reference for 5W-40 and 0W-40 and FWIW :
http://www.wrightune.co.uk/downloads/approved_oils.pdf

sjanes

I'm switching to synthetic diesel oil for my 911 now that Mobil 1 has changed from API SL to API SM.

ltc

You're baiting him, aren't you?

sjanes

Nope. Although I'm not sure about the diesel thing yet, it is an option, adding GM EOS is another. The Mobil1 15/50 I used to buy was API SL, but the new stuff (5/50) is API SM. From different things I've been reading, and from what my mechanic has been seeing, the lower Ph and Z level in the API SM stuff is causing excess wear in cams and rockers in the air cooled engines.

It's been discussed on the 911 boards of Pelican and Rennlist with a lot of debate.

chrisp

plus some knowledgeable folks say use the lowest viscosity you can to get the oil pressure you need.

DJF1

http://www.mobil1.com/USA-English/Mo...1_15W-50_.aspx

The new Mobil 1, hopefully the old staff...keep fingers crossed!

ltc

I still have 10 5 qt containers of the 'old stuff' in my basement.
How are we supposed to tell if the 'new M1 15W-50' is the same as the 'old'?