Certainly it seems many use Synergyn Race oils in Nascar. See info below I pulled from their site.The LTS 3w-30 is the one,,they also have a lighter wt "qualifying oil"
TYPICAL SPECIFICATIONS
SAE Grade LTS 3w- 30* 5w-30 5w-50
15w-50 50 Wt. 70 Wt.
Viscosity
@40 Degrees C 67.8 77.9
119 162 203 305
@ 100 Degrees C 10.7 12.3
17.6 20.9 20.6 28.1
Viscosity Index 146 156
162 154 120 124
API Gravity 29.12 29.2
29.15 28.6 26.4 26.1
Specific Gravity 0.881 .8805
.8808 .8840 .8960 .8970
Density, Lbs/Gal. 7.35 7.33
7.34 7.36 7.46 7.47
Flash Point, Degrees F 410 406
410 410 411 411
Pour Point, Degrees F -40 -30
-36 -20 -18 -15
Anti-Wear Exceeds
All Requirements
Dispersant Exceeds
All Requirements
Anti-Scuff Exceeds
All Requirements
Rust Inhibitors Exceeds
All Requirements
Anti-Foam Exceeds
All Requirements
* LTS 3w-30 was developed for Winston Cup Racing. It contains the
ultimate additive system for
high rpm, high speed, high temperature conditions where thermal
stability and the prevention of
oil thinning/breakdown are essential.