[Blueclyde]

How many of you guys tracking ZLEs are using Mobile 1 15w-50?

[Beescuz]

I do. That is all I use for track days. Have 45 track days on the car with no issues using that oil.

[LancevanceZLE]

Originally Posted by Beescuz

I do. That is all I use for track days. Have 45 track days on the car with no issues using that oil.

Do you drive the car to the track on 0w40, then switch to 15w50 at the track, and then switch back to 0w40 for the drive home?

That seems very impractical, time consuming and expensive.

[GreenZLE]

Originally Posted by LancevanceZLE

Do you drive the car to the track on 0w40, then switch to 15w50 at the track, and then switch back to 0w40 for the drive home?

That seems very impractical, time consuming and expensive.

I change to 15W-50, sometimes a week or 2 before the event, run the track, and change the oil when I get home. If you do 2 full track days, the oil needs changed again anyway.

[Beescuz]

Originally Posted by LancevanceZLE

Do you drive the car to the track on 0w40, then switch to 15w50 at the track, and then switch back to 0w40 for the drive home?

That seems very impractical, time consuming and expensive.

No. I run 15w-50 in my car all the time. I track the car more than drive on the street. As long as you don't rev the car when the oil is cold you won't have any issue running 15w-50 all the time. I have had the car two years purchased new and currently have right at 9,000 miles on the car (7,000 miles track). No issues.

[Blueclyde]

Originally Posted by Beescuz

No. I run 15w-50 in my car all the time. I track the car more than drive on the street. As long as you don't rev the car when the oil is cold you won't have any issue running 15w-50 all the time. I have had the car two years purchased new and currently have right at 9,000 miles on the car (7,000 miles track). No issues.

Thanks for the feedback. I have a new 23 and am going to be tracking it for the first time. I went with the 15-50 because it was all that was on the shelf at the local A/P store. I agree with your comments on keeping rpm low until the oil gets warm. It’s probably not an issue at all, other than in Northern winter temps. I trailer my car to the track.

PS - This 23 replaced an 18 and I’m surprised how much higher the oil pressure reads on the gauge on the 23.

[Stephen12ZL1]

I use Motul 300v 5w40...oil temps on track are 15-20 degrees more with 15w50 due to the oil pump working harder to pump that thick syrup. The fact GM hasn't really nailed down a perfect viscosity recommendation leads me to just about anything will suffice. 5w40 Valvoline MST used to be an approved oil for the LT4 and now 0w40 is the factory fill when 5w30 was factory fill in 2017...so WTF? Nothing is perfect and use what makes you happy...remember even the recommended 15w50 for track use isn't Dexos certified.

[Blueclyde]

Originally Posted by Stephen12ZL1

I use Motul 300v 5w40...oil temps on track are 15-20 degrees more with 15w50 due to the oil pump working harder to pump that thick syrup. The fact GM hasn't really nailed down a perfect viscosity recommendation leads me to just about anything will suffice. 5w40 Valvoline MST used to be an approved oil for the LT4 and now 0w40 is the factory fill when 5w30 was factory fill in 2017...so WTF? Nothing is perfect and use what makes you happy...remember even the recommended 15w50 for track use isn't Dexos certified.

Agreed. The biggest issue I have is you can’t find any of the newer recommended oils on a local A/P store shelf. None of the big stores here in Metro Detroit, at least near me, carry it. I plan on changing my oil after returning from CFest and I’ll go with a 5-40 or 0-40 when I do that. I might have to start ordering my oil from Amazon.

[Zl1+911]

One thing that I have not been able to find is the relative viscosity difference between 0/40 and 15/50 at operating temp. Obviously 50 is more viscous than 40, but at operating temp on track (say 240) what’s the exact difference in viscosity? Is it material? Does anyone have insights with some data on this? Thx!

[SCCAForums]

I have switched to the new SuperCar 5w50 (for my Katech SS 1LE).

I did run 15w50 in my ZLE, year round (AZ weather).

Best regards,
Dave

[NorthGeorgia]

15w50 all the time (Georgia) - 8,000 miles track / 20,000 miles total

[synolimit]

Nope. Redline here. Way more moly and protection.

[wakespeak]

15w-50 here mostly to all year. I saw oil analyses on bobistheoil.com with some LT4s with mixed street/track with 15w-50 and results were fine. The one thing I don't like is carbon coking on the dip stick.

19k miles on car, about 9k track miles.

I use Motul 300v 5w-40 otherwise and the engine seems to like it. Its a thicker 40 grade with ether oil base.

[wakespeak]

Originally Posted by Zl1+911

One thing that I have not been able to find is the relative viscosity difference between 0/40 and 15/50 at operating temp. Obviously 50 is more viscous than 40, but at operating temp on track (say 240) what’s the exact difference in viscosity? Is it material? Does anyone have insights with some data on this? Thx!

With 15w-50 I see regular 275F-280F temps on the track. Not used xw-40 on the track and would be interested in seeing results.

In theory xw-40 should run cooler due to the reduced fluid friction mentioned above. GM recommends the higher viscosity oil for cornering protection, then only for the ZL1 1LE.