Its not the oil viscosity .
Oil weight, or viscosity, refers to how thick or thin the oil is. The temperature requirements set for oil by the Society of Automotive Engineers (SAE) is 0 degrees F (low) and 210 degrees F (high). The oil will be stable to the high limit operating zone .Are you suggesting the oil is far exceeding 300 to 400 F ?


6.50 @ 226 MPH 4.25 @ 186 MPH
https://www.youtube.com/watch?v=YX86DHGKBo0