ALTECH

The other day at a track, with my 07 Z, the oil was at 230 degrees and the oil pressure was about 40psi at any rpm. I called a VERY well known tuner/engine builder and ask if I could use 10W30 or 0W40; he answerd 0W40.

Also, could we use 15W50 like the C6R? Since it seems that our oil pumps are NOT the best.

What do you people think?

NocarbutaVetteforme

Go with what the tuner told you. They tend to know quite a bit more especially when it comes to the stuff you should use at a track. Most of them have some sort of track attachment anyway. Most of them race at the tracks and know what to use from experience.

ICC

I ran 15-50 M1 in my C5 Z (LS6) at track events with no problem. When I got the C6, with the LS7, it wasn't that hot at the track and ran 10-30 M1. When things started to get warm outside, I switched to Amsoil 10-40 and haven't looked back.

BTW, I change my oil and filter after every event and recycle the oil (give it to my friends who run it in their passenger cars).

Bills Z06

I agree with previous post. Go with what your tuner suggests - lots of hands on experience.

jmc5

230 is not very hot. 40 psi at any rpm sounds far more like a broken/weak pressure release, or maybe even a broken gauge.

Oil that's too thin doesn't have some magic way of staying at one pressure, its just so thin that it doesn't hold enough pressure. If you'd said "It was 5 psi in the pits, and 40 psi at 7k rpm", that (might) be a sign of needing heavier oil.

I'd stick with the factory recommended stuff until you can diagnose what the real problem is.

C66 Racing

Most of the below data is for oils way outside what is required by your owner's manual, so you'll have to make your own decisions here. In my 02 Z06 I use the AMSOIL SAE 10w40 Formula 4-Stroke Marine Synthetic Motor Oil because this oil isn't limited by the new, more restrictive API SM standards, was designed for sustained high rpm, high load conditions (like on the track), and contains rust inhibitors (which helps my frequently stored car). I think this shows in the this oil's High Temp High Shear (HTHS) rating of 4.6, the same as the Mobil 1 EP 15w50, but in a 40 weight oil.

The High Temperature/High Shear Test measures a lubricant’s viscosity under severe high temperature and shear conditions that are similar to severe service applications in an engine. Here is a listing of HTHS numbers I recently pulled off various manufacturers websites. This shows that while the Mobil 1 0w40 has a much higher HTHS rating that the Mobil 1 5w30, there are better choices if you are going to stray from the owner's manual requirements.

Amsoil Series 2000 20w50 (API SM) – 5.8
Amsoil Premium Protection 20w50 (API SL) – 5.0
Amsoil Marine Synthetic 10w40 (API SL) – 4.6
Mobil 1 EP 15w50 (API SM) – 4.6
Pennzoil Marine SAE 40 (API SJ) – 4.5
Amsoil Heavy Duty Diesel 15w40 (CI-4+) – 4.4
Amsoil Premium Protection 10w40 (API SL) – 4.3
Amsoil XL 10w40 (API SM) – 4.3
Pennzoil Truck/SUV 15w40 (CI-4+) – 4.3
Pennzoil Long Life Heavy Duty 15w40 (API SL) – 4.3
Amsoil Premium Diesel 5w40 (CJ-4) – 4.2
Mobil 1 High Mileage 10w40 (API SL) – 4.06
Pennzoil Marine 15w40 (API SL) – 4.0
Amsoil European 5w40 (API SM) – 3.7
Mobil 1 High Mileage 10w30 (API SL) – 3.66
Amsoil Marine Motor 10w30 (API SL) – 3.64
Mobil 1 0w40 (API SM) – 3.6
Amsoil Heavy Duty Diesel 5w30 (CI-4+) – 3.5
Pennzoil Long Life Heavy Duty (API SL) – 3.5
Pennzoil Marine SAE 30 (API SJ) – 3.5
Amsoil Series 2000 0w30 (API SM) – 3.2 (meets GM Standard 4718M)
Amsoil SAE 10w30 (API SM) – 3.2 (meets GM Standard 4718M)
Amsoil SAE 5w30 (API SM) – 3.2 (meets GM Standard 4718M)
Amsoil XL 5w30 (API SM) – 3.2 (meets GM Standard 4718M)
Amsoil XL 10w30 (API SM) – 3.2 (meets GM Standard 4718M)
Amsoil XL 5w30 (API SM) – 3.2 (meets GM Standard 4718M)
Pennzoil Platinum 10w30 (API SM) – 3.15 (meets GM Standard 4718M)
Mobil 1 10w30 (API SM) – 3.14 (meets GM Standard 4718M)
Mobil 1 EP 10w30 (API SM) – 3.1
Mobil 1 EP 5w30 (API SM) – 3.1
Pennzoil Platinum 5w30 (API SM) – 3.1 (meets GM Standard 4718M)
Pennzoil Truck/SUV 10w30 (API SM) – 3.1
Mobil 1 5w30 (API SM) – 3.09 (meets GM Standard 4718M)
Mobil 1 Truck/SUV 5w30 (API SM) – 3.09
Pennzoil Truck/SUV 5w30 (API SM) – 3.0
Mobil 1 0w30 (API SM) – 2.99 (meets GM Standard 4718M)
Amsoil SAE 0w20 (API SM) – 2.8
Amsoil XL 5w20 (API SM) – 2.7
Mobil 1 EP 5w20 (API SM) – 2.7
Mobil 1 5w20 (API SM) – 2.62
Mobil 1 0w20 (API SM) – 2.61
Pennzoil Platinum 5w20 (API SM) – 2.6
Pennzoil Truck/SUV 5w30 (API SM) – 2.6
Pennzoil Platinum 0w20 (API SM) – 2.6

Data verified from corporate websites May 07.
Note: Many companies such as Shell Rotella T and Royal Purple do not list HTHS ratings

catbert

I'm sure some tuners are very knowledgeable about oil. I know for sure some of them are not. If you stay with factory specs (GM4718M), not necessarily factory brand, any problem will be covered by warranty. Outside of warranty, I'd be even more careful. Sheer numbers aren't the only important factors in oil choice.

But that's just me.

songman3

For your information, here`s a couple of photos of a sticker on the door pillar of my June 2007 Euro spec C6Z06 - hope this helps

[IMG][/IMG]

[IMG][/IMG]

RoHo

Sub, I noticed that Castrol synthetic was not on this list, is there a reason why.

Very good info, thanks for sharing

Pio

0w40 is what Mercedes and Porsche use. I will probably try it out in my C6Z. My tuner recommended 15w50 for my forged / blown 416.

C66 Racing

Like Royal Purple, Castrol doesn't share their HTHS numbers on their product data sheets.

ALTECH

WOW... That says it all!!!

Thank you