Which Oil for tracking?

[S54330Ci]

I ran 0w-40 in my S54 and the oil temps got higher faster but cooled much faster when I backed off. 10w-60 takes longer to get hot but takes two laps to cool down. I wonder if a 50wt oil is the happy medium.

For track use I would never suggest 0w-40, way too thin for the S54 that will live at 5000 - 7800 RPM on the track. Maybe if you lived in San Diego . . . and didn't drive it hard (but then what's the point of owning an M3?)

Single weight oils (i.e. 50wt) would prove too thick for colder climates and likely result in accelerated rod bearing wear if the engine is pushed hard before the oil is at operating temperature.

Purely one person's opinion - YMMV.

[elbert]

For track use I would never suggest 0w-40, way too thin for the S54 that will live at 5000 - 7800 RPM on the track.

If you read some of the older BITOG posts, TWS will shear down to thicker 40 wt fairly quickly. Could just be internet lore, who knows.

[S54330Ci]

If you read some of the older BITOG posts, TWS will shear down to thicker 40 wt fairly quickly. Could just be internet lore, who knows.

Well . . . if that is the case, what would 0w-40 shear down to?

IMO 0w-40 is too thin for track use.

[CrookedCommie]

I've ran Redline 50WT. Stopped after the blackstone reports came back. Redline has been shit everywhere I've used it.

[elbert]

Well . . . if that is the case, what would 0w-40 shear down to?

It depends on the specific oil and how much thickeners it uses. Some don't drop much at all, some will take a while, some quicker than that.
On the flip side, there might be some 10W60 oils that end up being too thick.

Generally speaking, I do agree a 0W40 would probably be a little too thin for track work, but a 10W40 might do well since it has a thicker base stock and will have less viscosity improvers.

[bigjae46]

For track use I would never suggest 0w-40, way too thin for the S54 that will live at 5000 - 7800 RPM on the track. Maybe if you lived in San Diego . . . and didn't drive it hard (but then what's the point of owning an M3?)

Way too thin? Oil pressures were normal even when the oil was at 300 degrees. Hit 78psi at about 6k rpm which is about the same as BMW 10w-60. Part of the heat issue was the track. It was the Milwaukee Mile. Its a tight 1 mile oval with an infield so you're in 2nd gear which is what causes temps to really shoot up.

I'd run it again except it didn't help with the peak oil temps. Figured I needed more cooling.

[S54330Ci]

Well, I respect your point of view, and you are certainly free to run whatever oil you are comfortable with in your engine. I'll continue running 10w-60 in my tracked S54 until I get a clear and concise reason from BMW that a lower viscosity oil will provide the same OR BETTER protection than the 10w-60.

[Cronenberged]

Amsoil has a 10w60 now, but as other have stated stick with that and OE. Pennzoil would be the next best then liquid moly and Castrol if looking at shear and viscosity.

[Feffman]

Good day all. I'm attaching the10W-60 oil spreadsheet I've put together over the past few years. All the information is from the manufacturers published information. I have it in an Excel spreadsheet as well. If you'd like a copy, e-mail Feffman@MVPTrackTime.com.

Feff

[Slideways]

Easy answer - whatever 10-60 FCP offers

1. BMW (rebranded Castrol) 10-60
and when they stop offer that
2. Motul 10-60
and when they stop offering that
3. Liqui Moly 10-60

Other options
Porsche (probably rebranded Mobile 1) 10-60
Redline 10-60

[Tbonem3]

Well, I respect your point of view, and you are certainly free to run whatever oil you are comfortable with in your engine. I'll continue running 10w-60 in my tracked S54 until I get a clear and concise reason from BMW that a lower viscosity oil will provide the same OR BETTER protection than the 10w-60.

Make sure to look at the actual viscosity numbers because there are 5w50s that are heavier than some 10w60s just like there are 265/35/18 tires that are wider than other brands' 275.

Liquimoly 10w60 is quite heavy (something like 26 cst @100) where as castrol is more like a 40 weight.

[IamFODI]

Make sure to look at the actual viscosity numbers because there are 5w50s that are heavier than some 10w60s just like there are 265/35/18 tires that are wider than other brands' 275.

Liquimoly 10w60 is quite heavy (something like 26 cst @100) where as castrol is more like a 40 weight.

For kinematic viscosity at 100º C, a.k.a. KV100 – the thing that determines the big number in the viscosity rating (40, 50, 60, etc.) – there's no overlap. Any xW-60's KV100 is always higher than any xW-50's, which is always higher than any xW-40's, etc.

Where you will see overlap is in other viscosity measurements, e.g. kinematic viscosity at 40º C or high temperature high shear (HTHS) viscosity. That's where you could have a "lower" viscosity grade that ends up with a higher viscosity measurement than a "higher" viscosity grade – e.g., a 5W-50 with a higher HTHS viscosity than a 10W-60.

[Tbonem3]

And that's what matters. I don't care much about a VOA, more a UOA since oil is never new except for that first fill up. Oil with high quality stock will shear less no?

[IamFODI]

And that's what matters.

HTHS, you mean?

I tend to agree, but AFAIK the reality is more complex. The more I learn about this stuff, the less I feel I know...

Oil with high quality stock will shear less no?

Generally, yeah. Very hard to tell what the base stocks are, though.

Can even be hard to tell shear, because viscosity loss could also be due to fuel dilution, which not all UOAs reliably catch (including the ones that have it as a line item).


If we want to talk about what really matters, it isn't any one spec, performance metric, or collection thereof; it's the performance of the formulation as a whole – how long engines live with it, on average. We can make a low-quality guess about this from looking at specs. We can make a slightly better guess from used oil analysis. But if we want to know, that takes real engine testing – the kind of thing no one outside of OEMs and a tiny fraction of engine builders (e.g. Cosworth) can afford to even contemplate.

For our engines, there's only one party that has done that testing, and that's BMW M. That means the only oil backed by that level of knowledge is BMW's own 10W-60. Everything else is a guess (varying levels of educated).

[trackjunky]

HTHS, you mean?

I tend to agree, but AFAIK the reality is more complex. The more I learn about this stuff, the less I feel I know...



Generally, yeah. Very hard to tell what the base stocks are, though.

Can even be hard to tell shear, because viscosity loss could also be due to fuel dilution, which not all UOAs reliably catch (including the ones that have it as a line item).


If we want to talk about what really matters, it isn't any one spec, performance metric, or collection thereof; it's the performance of the formulation as a whole – how long engines live with it, on average. We can make a low-quality guess about this from looking at specs. We can make a slightly better guess from used oil analysis. But if we want to know, that takes real engine testing – the kind of thing no one outside of OEMs and a tiny fraction of engine builders (e.g. Cosworth) can afford to even contemplate.

For our engines, there's only one party that has done that testing, and that's BMW M. That means the only oil backed by that level of knowledge is BMW's own 10W-60. Everything else is a guess (varying levels of educated).

100% agree ^

I always run Castrol 10w60 with BMW OE filters. avg of 20 track days a year, for the past 12 years. Oil analysis on every oil change. Oil changed every other event.