Mobil 1 0w40 - Supercar or FS?

[BoilerUP]

New member here, have done multiple searches but didn't quite find what I was looking for so decided I'd start a thread.

I have a 2018 Cadillac ATS-V with 3.6LL TT LF4 engine. This engine was installed in December 2023, after spinning a rod bearing on my original (modified, 600whp with E48 blend fuel) LF4 on track at Gingerman while using spec Mobil1 FS 5w30 oil that had one track day/1.5hr on it. That proved to be an expensive mistake.

The current LF4 is completely stock, but I have recently been running Supercar 0w40 since it has higher KV100 and HTHS than Mobil1 5w30.

Blackstone UOA has shown after two track days (2-4 hours on circuit) that Supercar 0w40 sheers to a heavy 30 weight in 10.8-11.0 KV100 range, which is more than 2 points higher than M1 FS 5w30 with the same amount of track days/hours on it.

I have seen that M1 FS 0w40 is now API SP, and it seems to have a bit higher KV100 than Supercar 0w40 though I've seen folks here say they likely have the same HTHS in the 3.5-3.6 range. Supercar 0w40 is not API SP, but meets GM Dexos R and is the spec oil for the direct injected LT1 V8, which admittedly isn't a twin turbo application. It appears virgin FS 0w40 API SP oil has about ~200ppm less calcium than Supercar 0w40 based on VOAs I've seen here; FS 0w40 is also available at big box stores near my house where I have to order Supercar 0w40 online.

A replacement engine, turbos, and oil cooling system wasn't cheap, so I'm trying to mitigate certain risks to engine longevity given my use case. Everybody has opinions (especially on BITOG!) so I ask the braintrust: if this was your engine, would you keep running Supercar 0w40 or switch to FS 0w40 API SP?

Thanks for the insights...

 

[kschachn]

First off, those Blackstone analyses are unable to distinguish a viscosity deviation due to mechanical shear of the VM and fuel dilution.

Second, if you’re tracking a car like that, I’d use a track oil that is recommended by the blender after detailing to them my track conditions. Whether or not the oil has an API license (SP or otherwise) is utterly irrelevant here.

Call up Red Line or HPL and get a recommendation.

 

[JavierH19]

Oil temps could've gotten high enough to make that 3.5+ hths oil insufficient or you momentarily lost oil pressure which is what I think happened. Do you have an oil accumulator? if not I'd get one first thing.

 

[Jetronic]

Oil temps could've gotten high enough to make that 3.5+ hths oil insufficient or you momentarily lost oil pressure which is what I think happened. Do you have an oil accumulator? if not I'd get one first thing.

Agreed, the sump shape plays a big role in keeping the oil pickup submerged on track. Remember, when braking or turning at 1G the oil sits at a 45 degree angle in the pan. Some oil pans look like a bathtub, and it's not hard for all the oil move away from the pickup in those.

 

[buster]

Supercar 0w40 and M1 0w40 are track oils. Either would be fine.

For something more shear stable I'd look to Amsoil, HPL or Red Line. But those are not even proven to be better. You'd have to tear down the engines to really know. UOA's are imperfect tools. Ditch B/S Labs and try Oil Analyzers.

GM also tested Mobil 1 0w40 ESP in the Corvette for 2 years.

Thread 'Porsche's own factory race team apparently uses M1 0w-40 FS'

Aug 12, 2021

I was fortunate enough to attend Porsche Rennsport Reunion at Laguna Seca Raceway back in 2018. It's a huge gathering where every conceivable model of Porsche is brought to a track and displayed and raced. One of my favorite parts of the event is that nothing is roped off and people can go right up to the cars and examine them or take pictures.

As I walked by the paddock I saw a few members of Porsche's factory racing team servicing a first generation 991 RSR. At the time I took this picture the car had been recently retired as Posrche was transitioning to a new mid-engined 991 RSR...

• Arcoril
• Replies: 53
• Forum: European and Import Motor Oils

• 

 

[BoilerUP]

Oil temps could've gotten high enough to make that 3.5+ hths oil insufficient or you momentarily lost oil pressure which is what I think happened. Do you have an oil accumulator? if not I'd get one first thing.

I was using M1 FS 5w30 when the bearing spun...I think its HTHS is around 3.1?

I did a LOT of stuff wrong in making that expensive mistake...1. OEM spec oil while 2. running 160whp over stock on 3. ethanol blend fuel which contributes to dilution and 4. doing HPDE with sustained oil temps north of 270F (I understand oil temp in this car is calculated, not actual).

Stupid should hurt, and it did.

I'm trying to be "better", and figured a ~14% increase in HTHS is a good place to start. I could run an even heavier oil, but this car is 40% street/60% circuit so I want to use an oil that doesn't cause overly high pressures on the street during the winter (I live in southern Indiana).

 

[JavierH19]

I was using M1 FS 5w30 when the bearing spun...I think its HTHS is around 3.1?

I did a LOT of stuff wrong in making that expensive mistake...1. OEM spec oil while 2. running 160whp over stock on 3. ethanol blend fuel which contributes to dilution and 4. doing HPDE with sustained oil temps north of 270F (I understand oil temp in this car is calculated, not actual).

Stupid should hurt, and it did.

I'm trying to be "better", and figured a ~14% increase in HTHS is a good place to start. I could run an even heavier oil, but this car is 40% street/60% circuit so I want to use an oil that doesn't cause overly high pressures on the street during the winter (I live in southern Indiana).

Do you remember if that bottle of m1 fs 5w-30 said european on it or not. If it didn't then it could have thinned out enough to cause a spun bearing without losing oil pressure. But it's good to have an oil accumulator on the track.

 

[kschachn]

I'm trying to be "better", and figured a ~14% increase in HTHS is a good place to start. I could run an even heavier oil, but this car is 40% street/60% circuit so I want to use an oil that doesn't cause overly high pressures on the street during the winter (I live in southern Indiana).

What’s an “overly high” pressure?

 

[BoilerUP]

What’s an “overly high” pressure?

I suppose my concern (valid or not) is if pressure is overly high with cooler oil temps, there may not be sufficient flow to properly lubricate everything...so I'm trying to hit a sweet spot between year-round streetability and being better at sustained oil temps on circut.

80psi at 90F oil temp (after a short warm-up) and 1500rpm leaving my driveway is where I start to pay more attention.

I've tried Supercar 5w50 and was seeing 80psi+ at WOT with oil at normal operating temp (190F)...I'm normally in the low 70s with Supercar 0w40 in similar operating conditions.

 

[Triple_Se7en]

Supercar!
You want an oil that can tackle the toughest jobs - even if the track times fall from 40% to 10/20%.
For the price of UOAs these days, change your oil twice as often instead.

 

[kschachn]

I suppose my concern (valid or not) is if pressure is overly high with cooler oil temps, there may not be sufficient flow to properly lubricate everything...so I'm trying to hit a sweet spot between year-round streetability and being better at sustained oil temps on circut.

80psi at 90F oil temp (after a short warm-up) and 1500rpm leaving my driveway is where I start to pay more attention.

I've tried Supercar 5w50 and was seeing 80psi+ at WOT with oil at normal operating temp (190F)...I'm normally in the low 70s with Supercar 0w40 in similar operating conditions.

If the pump is pumping then there is sufficient flow for lubrication. Flow never lubricated an engine anyway.

Considering the epic failure you experienced in trying to fine-tune this pressure, I’d suggest you listen to some of the advice in this thread and stop worrying about a phantom threat. Call a track oil blender and take their advice. They know what they are doing.

 

[4WD]

I suppose my concern (valid or not) is if pressure is overly high with cooler oil temps, there may not be sufficient flow to properly lubricate everything...so I'm trying to hit a sweet spot between year-round streetability and being better at sustained oil temps on circut.

80psi at 90F oil temp (after a short warm-up) and 1500rpm leaving my driveway is where I start to pay more attention.

I've tried Supercar 5w50 and was seeing 80psi+ at WOT with oil at normal operating temp (190F)...I'm normally in the low 70s with Supercar 0w40 in similar operating conditions.

Why does 80 psi bother you? - my soccer mom vehicles do that in high stage …

 

[edyvw]

Occasional track day, once in a blue moon, Mobil11 0W40, either FS or Supercar

However, it seems to me you are really good candidate for HPL BAS 5W40 or Motul 300V 5W40!

 

[BoilerUP]

Considering the epic failure you experienced in trying to fine-tune this pressure, I’d suggest you listen to some of the advice in this thread and stop worrying about a phantom threat. Call a track oil blender and take their advice. They know what they are doing.

The "epic failure I experienced" is what led me down this path in the first place, not the other way around.

Appreciate your input

 

[MalibuRam65]

I still can’t believe M1 oils are still shearing like crazy even after all these years and formulations changes. Smh

 

[6.7 CTD]

HPL Supercar 5W50 even though you don’t want 5W50

 

[kschachn]

I still can’t believe M1 oils are still shearing like crazy even after all these years and formulations changes. Smh

Which you are completely unable to determine from these UOA, shaken head or not.

 

[chris719]

Neither, ESP X3 or X4

 

[userfriendly]

Why 5W and 0Ws then complain about viscosity loss, are these winter grades necessary for your application?
Have a look at M1 15w50. It was the recommended oil for Corvettes on track days not that many years ago.

 

[38Chevy454]

Is cold weather happening when you are doing track days? I think no, and they are different seasons. The easy solution is run the thinner "street" oil in winter, and then change to thicker "track" oil in summer or when you are doing track days. So you end up changing oil more often, only real issue is small amount of additional money.

I also think an accumulator is a good idea.