So bought the car - the indy that did the PPI also services the car for the owner when he had it and did the oil changes. They said they ran and recommend running Motul 15w-50.

Car runs perfect - used less than a quart on the way home (2000miles) so i've got no problem continuing to do so but in the owners manual a 15w-50 is not an approved weight and so the oil pressure readings aren't reading the same as they should in the owners manual either.

At idle it's around 2.5-3bar and anything over 2k rpm and it's between 4-5bar (mostly around 4.5bar). Is this normal? Am I hurting anything?

I live in Nebraska so today it's 105 out but in a few months it will be getting down to 0 degrees. And while I don't plan on driving the car in the snow I do plan on using it sporadically in snow-free 30-40 degree days (might as well use those heated seats). Do I risk anything running this oil on the engine?

 

Hi, Some say 15W is to thick for the variable cam system ?

 

0w40, 5w40, and 5w50 are all approved weights for the GT1 996tt engine. I've run the M1 0w40, M1 5w40TDT and the M1 5w50. 15w50 is way too thick and that is why you're seeing such high idle oil pressures. Hot idle with the 0w40 and 5w40 you should see 1.4-1.6 bar and with the 5w50 1.5-1.7bar, give or take. The Gt1 motor is a tight clearance engine and requires a lower viscosity oil for full lubrication and for the vanos to work properly. You do not need molasses for lubrication even though it may make the engine quieter and give you a false sense of security.

 

Todd knighton long with a few other tuners recommend 20w50 ... thats what i use .

there are posts and horror stories about engine failures using low weight oil.

i run amsoil high zinc 20w50.

 

15w is way too thick for colder temperatures IMO. If you drive it in cold weather, the only weight I would use is 0w and maybe 5w.

Overall, I think 5w50 is perfect. I don't understand the reasoning behind the thought that 20w50 would be better. The first number only applies to cold startups. The second one matters for a hot engine.

Especially on FI'd cars, you don't want to run oil that is too thick; the turbo or supercharger won't like it very much.

 

I agree with the 15w50 and 20w50. High zinc is also a must. In colder climates allow the motor to warm up before drivings at higher rpm's. Porsche recommends you get in the car and drive. Thats for emission reasons, so to do that you need low "W" oil. I can show you what wrist pins look like on 0w40 If I still have them

 

Aaaaanndd there you have it .

 

Really...and you have scientific proof this is due to the weight of the oil...NO WAY. Lots of anecdotal stories and myths about oil weight as you can see by just searching. Best data based study ever done on Porsche is by Doug Hillary. You really should search for his threads on the subject...they contain actual data.

The OPs car is not heavily modded...I would stay within the recommended Porsche weights as specified above. The oil is used for not only lubrication, but for cooling as well. Flame on!

 

There is a guy on here with over 200k miles on his 996TT with M1 0w40 oil from day one. I currently run 5w40TDT. Close this thread, another oil debate... Lol!

 

I would never run 0W40 in my motor because of my mod package and the way I drive...UNLESS it was only staying in for the winter..
I use 5W40 or 10W40 because of the additive package..
To each his own with their baby..

 

i have been using 20w-50 with zync additive.

 

I use 0w40w mobil one with BJ ZZDP zinc additive(2 bottles/oil change)

 

Here we go... I use extra virgin olive oil in mine. Makes the greatest smell!

 

Motul 20w60. Amazing oil..

 

I'm in SoCal so it doesn't get very cold ... No issues to report.