Nascar oil

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Nov 2, 2021
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Just spent an hour web surfing all I get is over 50% nascar teams choose mobil 1, but how about weight?
 
Interesting I can see the 50wt but needing a winter rating is a head scratcher
 
Only a handful use Mobil 1. The biggest group of them (by far) use an oil from Driven (formerly Joe Gibbs). It has a KV100 of 7.0-7.5 cSt which is, in fact, about a 0W-16 equivalent. Sump temperature at Daytona is ~280°F with the oil temperature at bearing exit near 355°F. They use a 0W-5 for qualifying. They'll go about 4 races on an engine, only changing it then just to keep a fresh bullet in the hole. Excessive wear is uncommon, and engine failures (in general) are even less common.
 
Oh, I don't know, common sense perhaps? And the fact that for years NASCAR always qualified on the super speedways, with far thinner viscosity oil than they raced with. Why do you suppose that was?
One thing for sure, they make better decisions then you and I.
 
None of them are using a 0W-50. There may be a handful using 0W-30, but they aren't leading the pack. A 0W-50 would be detrimental to those engines, as the ring thickness/tension and hone peaks are far too low for that much of an oil film (aka poor ring seal + high oil drag) and the amount of VII needed for that would make the oil too volatile, which paired with the high oil film thickness would mean a lot of oil transport past the rings into the chambers causing detonation galore. The bearings would likely suffer from heat fatigue from the hydrodynamic friction. They already see ~75°F oil temp rise through the bearings as it is, with a 0W-16, from hydrodynamic friction. One of the reasons they run such a light oil, aside from power, is to keep down bearing temp rise and ensure high flow through the bearings at all times. They only run ~40 psi oil pressure at full tilt, but they're send a ton of oil through the engine every minute.

The 0W-16 equivalent they use is straight base oil with no VII.

Outside of 3000+ hp Pro Mods and Top Alcohol Dragsters, not many teams in Motorsports use 50 grade oils anymore. Even WOO Sprints don't use 50 grades anymore.
 
None of them are using a 0W-50. There may be a handful using 0W-30, but they aren't leading the pack. A 0W-50 would be detrimental to those engines, as the ring thickness/tension and hone peaks are far too low for that much of an oil film (aka poor ring seal + high oil drag) and the amount of VII needed for that would make the oil too volatile, which paired with the high oil film thickness would mean a lot of oil transport past the rings into the chambers causing detonation galore. The bearings would likely suffer from heat fatigue from the hydrodynamic friction. They already see ~75°F oil temp rise through the bearings as it is, with a 0W-16, from hydrodynamic friction. One of the reasons they run such a light oil, aside from power, is to keep down bearing temp rise and ensure high flow through the bearings at all times. They only run ~40 psi oil pressure at full tilt, but they're send a ton of oil through the engine every minute.

The 0W-16 equivalent they use is straight base oil with no VII.

Outside of 3000+ hp Pro Mods and Top Alcohol Dragsters, not many teams in Motorsports use 50 grade oils anymore. Even WOO Sprints don't use 50 grades anymore.

I bet you $20 there is an old video somewhere of a 0W50 being blended for Tony Stewart. The video is possibly ancient but it has to exist somewhere.
 
I bet you $20 there is an old video somewhere of a 0W50 being blended for Tony Stewart. The video is possibly ancient but it has to exist somewhere.

I wouldn't doubt it as it was probably a marketing campaign for Mobil 1 with no actual relevance to the real world. It's like videos showing teams pouring in oil from a Mobil 1 jug, though it isn't Mobil 1 oil in the jug. Such as that is more common that you might think. Gotta keep the sponsors happy in front of the cameras.

It's been >30 years since 50 grade oils saw widespread use in NASCAR.

Marketing is (sadly) full of deception like that. "See everyone! Tony Stewart trusts Mobil 1 Racing 0W-50 for his car... AND YOU SHOULD TOO!!!" lol
 
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I'm going to take a big chance here, and go way out on a limb, and say it's NOT 0W-16.

Might be 0W-8.

Funny cars use 0W-2...

Remember, NASCAR cars (driving ina circle. Ooo-wee..........) run a 36psi pressure cap on the cooling system or something crazy like that.

If they use a regular grade oil I would be surprised, because then you could make the argument that they would just use the thickest stuff they can find (40W-70?) to maintain viscosity for hours at 150-200MPH........... Which I do not think is how they do it...

Wonder if they use a Group V oil..

@High Performance Lubricants I have done nothing but speculate so far, but, do you know? About NASCAR?
 
None of them are using a 0W-50. There may be a handful using 0W-30, but they aren't leading the pack. A 0W-50 would be detrimental to those engines, as the ring thickness/tension and hone peaks are far too low for that much of an oil film (aka poor ring seal + high oil drag) and the amount of VII needed for that would make the oil too volatile, which paired with the high oil film thickness would mean a lot of oil transport past the rings into the chambers causing detonation galore. The bearings would likely suffer from heat fatigue from the hydrodynamic friction. They already see ~75°F oil temp rise through the bearings as it is, with a 0W-16, from hydrodynamic friction. One of the reasons they run such a light oil, aside from power, is to keep down bearing temp rise and ensure high flow through the bearings at all times. They only run ~40 psi oil pressure at full tilt, but they're send a ton of oil through the engine every minute.

The 0W-16 equivalent they use is straight base oil with no VII.

Outside of 3000+ hp Pro Mods and Top Alcohol Dragsters, not many teams in Motorsports use 50 grade oils anymore. Even WOO Sprints don't use 50 grades anymore.
20+ years ago I heard Jeff Gordon complain to his crew chief that he had less than 10psi oil pressure during caution laps. I was wearing one of those headsets you could hear them over their radio. The crew chief told him “don’t worry, you’ve got more horsepower with that thinner oil”. Guess who won the race??
 
Might be 0W-8.

Funny cars use 0W-2...

Remember, NASCAR cars (driving ina circle. Ooo-wee..........) run a 36psi pressure cap on the cooling system or something crazy like that.

If they use a regular grade oil I would be surprised, because then you could make the argument that they would just use the thickest stuff they can find (40W-70?) to maintain viscosity for hours at 150-200MPH........... Which I do not think is how they do it...

Wonder if they use a Group V oil..

@High Performance Lubricants I have done nothing but speculate so far, but, do you know? About NASCAR?

Pro Stock uses a 0W-2. FC/TF uses SAE 70.

NASCAR mandates a 33 psi cooling system pressure relief. At one point, they were running as high as 80 psi coolant pressure before NASCAR started regulating it.

They don't use a majority group V as that would be detrimental to anti-wear and anti-friction additive performance. I can't giveaway specifics, but the group V use is between 0-30%.
 
Pro Stock uses a 0W-2. FC/TF uses SAE 70.

NASCAR mandates a 33 psi cooling system pressure relief. At one point, they were running as high as 80 psi coolant pressure before NASCAR started regulating it.

They don't use a majority group V as that would be detrimental to anti-wear and anti-friction additive performance. I can't giveaway specifics, but the group V use is between 0-30%.
I believe Pro Stock is on 0W-5 One man for sure could give us a definite answer.
 
I believe Pro Stock is on 0W-5 One man for sure could give us a definite answer.

It varies in that range. Some call it SAE 0, some 0W-2, some 0W-5, some 0W-3, some 0W-8, etc.... but they're all within the same ~3 cSt KV40 range of each other. Aside from the 0W-8, these aren't official SAE oil grades so they can kinda call it what they want. The KV100 doesn't matter to those engines because they never get close to that hot. They're usually just 100-120°F oil temp at the starting line with a 10 quart sump.
 
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