Which Mobil 1 for a high strung-track rat?

[MCompact]

I have a 113,000 mile 1995 BMW 318ti that I drive on track days from time to time. While on the track engine speeds usually vary from @3500 to 6500 rpm. Ambient temperatures range from 70F to 90F. My owners handbook lists 5W-40 and 15W-50 as approved oils for the M42 motor. I'm wondering which of the following Mobil 1 oils would be the best choice for this application:
0W-40
5W-40 Turbo Diesel Truck
15W-50
I've used 15W-50 in the past with good results, but I'm wondering if a 5W-40 oil would be a better choice. Speaking of 5W-40, any thoughts on using Rotella T synthetic? Thanks for any and all advice!

 

[buster]

Mobil 1 TDT 5w40 is probably your best choice. Excellent oil.

 

[Solo2driver]

Price = Rotella T Synthetic 5w-40
If you must use M1-- TDT 5w-40 for that engine. No need for a 50-wt in that 4-cyl bimmer.

 

[benjamming]

What is your oil temp while at the track? This is crucial in selecting correct oil viscosity.

 

[MCompact]

Originally Posted By: benjamming
What is your oil temp while at the track? This is crucial in selecting correct oil viscosity.


I don't have an oil temperature gauge, but coolant temps rarely exceed 215F. The M42s aren't prone to running hot.

 

[CompSyn]

I’d have an oil temperature gauge installed and then not play the guessing game as to what viscosity for your racing application. Coolant temps and Oil temps are two separate animals.

 

[Doug Hillary]

Hi,
MCompact - As you have requested advice on two M1 products I would use (and do - as Delvac 1) M1 5W-40 TDT in your application. It is a different "animal" to M1 15W-50

Shell's Rotella T 5W-40 synthetic is a great product. I would use M1 5W-40 TDT though - again it is a different animal!

My Boxster regularly sees 6500rpm, operates at an ambient above 40C for long periods and runs with an oil temp. around >105C from time to time - the (Delvac 1)TDT lubricant is very "robust" at high temperatures

 

[TurboLuver]

5W-40 Turbo Diesel Truck... Hands down

 

[MCompact]

Thanks to everyone for their advice. I'm going with 5W-40 TDT.