[Try2paz]

Originally Posted by Junkyardspecial

I just purchased my ZLE but I know that the recommended oil has changed to 0w40 thru-out the range with no changes needed now.

Trying to prevent the spread of miss information but this is incorrect. The 1le required 15w50 for track duty. It’s labeled very clearly in the supplement package. This mobile 1 add you posted is just that an add.

I did the break in on the factory oil and switched to 15w50 full time. My car is mostly track

[Lafourche1]

Changing oils is part of the expense of track preparation. I would not (you are your own boss on this) put a used oil back into a car. The 15W/50W is required with the ZL1 1Le due to higher cornering loads. The heavier oil helps protect the engine under these track conditions. Conversely, the 5W/40W or 0W/40W oil is what is used for the street.

Just for clarity: The regular ZL1 can use the 0W/40W Mobil 1 Dexos II oil for street and track. Just change it a bit more regularly than the oil life indicator may indicate.

[unavailablezl1]

Originally Posted by Calubi

If the ZL1 1LE requires 15w50 for track use, and 0w40 for street use, how are people driving them to track events? Does everyone trailer their cars? Or change their oil at the track?

It would be no problem at all. My M3 had the OEM oil which used a specially made Castrol GTX 10w60 for BMW. That was some expensive oil.

[Junkyardspecial]

Originally Posted by Try2paz

Trying to prevent the spread of miss information but this is incorrect. The 1le required 15w50 for track duty. It’s labeled very clearly in the supplement package. This mobile 1 add you posted is just that an add.

I did the break in on the factory oil and switched to 15w50 full time. My car is mostly track

Yeah sorry I dug deeper and read the fine print on the ZLE package and GM said that as well. Ill be doing full time 15w 50 as well I have no cats anyway now to worry about.

[BAD MOOOFOOO]

From 'Ask Al':


The LT1 and LT4 engines are factory filled with 0W-40 Dexos2 oil. The 0W-40 Dexos2 engine oil is approved for both track and street use with the LT1 and LT4 (ZL1 only, not ZL1 1LE) engines. This is straight out of the owner’s manual.

For the ZL1 1LE, 15W-50 is the required track oil due to the increased lateral acceleration capability of the vehicle. It has enough of a grip capacity increase above all the other models that the added protection from 15W-50 is needed. The thicker 50 weight viscosity helps with oil pan drawdown when the oil gets hot on the track and reduces risk of pressure dropouts. For the ZL1, 15w-50 will add protection but is not required, as the 0w-40 was tested and provides adequate protection in a track environment.

Since Mobil 1 15w50 is not Dexos-certified, it is not recommended for long-term street driving use. Follow the Owner’s Manual and switch back to the 0W-40 Dexos-certified oil after your track session is over and you are back to street use.
With regard to the new Mobil 1 0W-40 ESP Dexos 2 oil, it is an acceptable oil for both the street and track, for the SS, SS 1LE, and the ZL1 due to having less aeration. However, it is not recommended for tracking your ZL1 1LE.

[mlee]

Originally Posted by Calubi

If the ZL1 1LE requires 15w50 for track use, and 0w40 for street use, how are people driving them to track events? Does everyone trailer their cars? Or change their oil at the track?

Originally Posted by BAD MOOOFOOO

From 'Ask Al':


The LT1 and LT4 engines are factory filled with 0W-40 Dexos2 oil. The 0W-40 Dexos2 engine oil is approved for both track and street use with the LT1 and LT4 (ZL1 only, not ZL1 1LE) engines. This is straight out of the owner’s manual.

For the ZL1 1LE, 15W-50 is the required track oil due to the increased lateral acceleration capability of the vehicle. It has enough of a grip capacity increase above all the other models that the added protection from 15W-50 is needed. The thicker 50 weight viscosity helps with oil pan drawdown when the oil gets hot on the track and reduces risk of pressure dropouts. For the ZL1, 15w-50 will add protection but is not required, as the 0w-40 was tested and provides adequate protection in a track environment.

Since Mobil 1 15w50 is not Dexos-certified, it is not recommended for long-term street driving use. Follow the Owner’s Manual and switch back to the 0W-40 Dexos-certified oil after your track session is over and you are back to street use.
With regard to the new Mobil 1 0W-40 ESP Dexos 2 oil, it is an acceptable oil for both the street and track, for the SS, SS 1LE, and the ZL1 due to having less aeration. However, it is not recommended for tracking your ZL1 1LE.

This also applies to Corvette with only the ZR1 required to use 15w50 on the track.

[SFV1LE]

No need to wait until you're at the track to change oil, that could be extremely difficult. They expect you to fill with 15w50, drive however far to event within a few hundred miles, run on track, and return before changing oil. If it's 1000+ miles to the track, you might want to change to 15w50 when you get there just to have fresh oil, and change before return so you aren't driving so far on track baked oil.

[Rodan]

Since this oil discussion is ongoing here, what about a ZL1 on ZLE rubber (or NT01/R888R/Hoosiers)...? One would assume the 15w50 specification would apply?

Thoughts?

[gotswap]

increased mechanical grip, probably safe to jump up to the 15w-50 oil

[Calubi]

So beyond the Dexos2 certification, what are the drawbacks to running 15w50 on the street? I've seen mention of decreased cat life, but what about engine life (assuming you drive like a granny until oil is up to temp)?

I know at the end of the day it's all about the risk you're willing to accept, in this case driving a few hundred miles on the street with 15w50 between track days. I just want to know what I'm getting into if I put for the 1LE.

[SFV1LE]

Originally Posted by Calubi

So beyond the Dexos2 certification, what are the drawbacks to running 15w50 on the street? I've seen mention of decreased cat life, but what about engine life (assuming you drive like a granny until oil is up to temp)?

I know at the end of the day it's all about the risk you're willing to accept, in this case driving a few hundred miles on the street with 15w50 between track days. I just want to know what I'm getting into if I put for the 1LE.

No real decreased cat life, it's street oil and ZDDP (Zinc) is not very high compared to M1 Racing Oil and other high ZDDP racing oils.

Engine life might actually be better due to greater film strength, resistance to viscosity breakdown, higher oil pressure at a given oil temp, etc.

The increased viscocity reduces power some from drag on crank.

Don't run 15w50 in cold climates due to poor flow at startup of cold engine. In warmer climates in morning, you need to be sure to warm up oil to full temp before WOT because of reduced flow when cold. That's the only concern I would have, other than voiding warranty if GM finds you're using it on street.

[Junkyardspecial]

Living in South Florida 15w-50 looks like a real all around oil for me then.

[Calubi]

So what would you consider minimum ambient temperature for cold start with 15w50?

[SFV1LE]

Originally Posted by Calubi

So what would you consider minimum ambient temperature for cold start with 15w50?

If you have to start it a couple of times early morning on a cold-snap track weekend, and its below 45 F, that's ok. But you definitely shouldn't run this oil for street in the winter anywhere that's often below 45 F, I'd say minimum average temp at start for daily use above 60 F.

In colder temps use Mobil 1 5w50 (Rally Formula or FS X2) if you prefer something heavier than 0w40. Almost the same as 15w50 but much better cold start flow.