i have M96 engine. and somewhere in LN Engg site recommending 5W40 to improve the life of IMS bearing. thats why.

Any side effects of using this 5W40 than 0W40?

 

FWIW quite a few people run the TDT or Delvac 1 oil without issue. It is an API SM oil (and CJ4) and designed to handle much harsher diesel engine conditions. However, it is not Porsche approved, so not sure why folks feel the need when 0W40 and the 5W50 both are and both have a proven track record (as does Castrol 5W40).

LN says to use a 5W40 because the IMS bearing EHL calcs apparently recommend it (I haven't done the calcs myself but I am taking their word for it). This is to meet the needs of the IMS only, not any other part of the engine, which was designed around using the 0W40. All Porsche racing teams run M1 0W40 FWIW.

The IMS EHL bearing calc goes out the window with the 2006 and later cars since they have a larger bearing than the 2005 cars (to help deal with the IMS issue). Even in the 2005 cars, the real issue seems to be not the viscosity but the lack of oil getting to the bearing. I have heard of no failures from folks that simply removed the factory bearing's seal so that fresh oil could get to it. However, since it is a pain to get to, many people just put in the stronger LN bearing while they are in there.

I bought a 2005 car that hadn't been driven for a long time so I decided to put in the LN kit as a proactive maintenance item (I also got a great deal on the installation). I run 5W50 because it is approved by Porsche, the car sees track use, and LN feels so strongly that it is better for the smaller diameter 2005 model bearing that I have. It also removed my Porsche's inherent, minor occasional smoke at startup issue that many cars have due to Porsche's engine layout (typically seen if you shut the car down after driving on the track and then start it up again soon after)

I would run any of the products mentioned in this thread without hesitation. For the New Jersey guy, I would run 0W40. For hotter climates or track use, perhaps the 5W40 or 5W50, though really only if you have a 2005 model car with the smaller IMS. Even 0W40 on track and 5W50 in the winter will all still work fine (Porsche runs 0W40 for Nurburgring 24hour races in their high strung cup cars...I think it can handle your commute). Go enjoy your car and stop worrying too much.

 

thanks a lot bergx7. Btw, i dont track at all.

i take your word for it. i will pick 0W40 9 qts while going home today. buying mobil 1 0w40.

http://shop.advanceautoparts.com/web...T|GRP2046_____

thanks all for the help.