Ur20v

Yep, slight chance the cats will loose some function (it is very slight) but huge gains in engine protection. You need to way up the risks and what will cost more if it failed. We don't have inspections here in Oz so will be running catless headers and suitable tune soon.

I've been running 0W-50 for 20000k on this car and many more on previous cars with no adverse effect to the cats performance (measured on a 5 gas analyser) so I am confident of no issue and prefer the extra and very real protection ZDDP gives to high load/wear items like rings, piston thrust surfaces, cam lodes, hydraulic lifters and bearings.

~$2000 for used headers or $50000 for a used engine, I know where my risk/money is...

JohnAnthony

mobil 1 5w50 is readily available on amazon.com
&
avlubes

mdrums

I've been running Motul 5w40 which is a Porsche approved oil...whatever that means...how does it compare to Mobil 1 5w50?

I got turned onto Motul 5w40 from the LN Engineering website.

deputydog95

Don't answer Mike. This will turn into a 15 page thread of follow questions and untold weeks of research on his part to eventually come full circle and keep using what he's using

85Gold

Now we degenerate into another OIL thread.



Peter

mdrums

Where is Rad when you need him?!?!

JB911

I went ahead and got 2 cases from http://www.avlube.com/mobil15w50.html

I guess it's the only 5W-50 approved by Porsche-
Mahle filter at ECS tuning

Best,
JB

911rox

The higher number references the viscosity of the oil when hot. The two would be similar when cold but the Mobil remains more viscous when hot and therefore will withstand greater heat without breaking down. Better protection technically with the higher temps typically seen on the track...

JB911

Mobil used to call it Rally 5W-50
Wonder what these guys run on their cars

fbirch

Wow!

WSH

I purchased Mobil 1 5w-50 at a local NAPA store here in Atlanta
Bill

mdrums

Not exactly in stone....a lot has to do the oil the base and additive package. Mobil1 5w50 doesn't necessarily protect your engine better than a top quality 5w40.

good reading:
http://www.lnengineering.com/oil.html
http://www.bobistheoilguy.com/puttin...nto-viscosity/

joyride5

+1 bought 15 cases last year...

911rox

Agreed Mike and there are other important factors like the Zn or Ph content of oils, cleaning additives, and so on... . Racing oils are closer to 1500ppm Ph like the mobil 1 Racing 0w-50 quoted by one poster, Mobil 1 reg is at 1000 ppm which is probably at least 200ppm less than the old standards... Many brands don't even quote figures...

At the end of the day, it seems all approved oils are of a standard that is designed to F up engines. I go with the factory fill brand (not neccesarily best) and IMO for track use the 5w-50 is far more suited to track use in heat than 0w-40 in the Mobil range...

Thats my non oil specialist opinion

Mvez

Motul 5W40 8100 X-Cess