I guess this goes to show Mobil1 0w40 is quite resilient.
This oil sample was sitting around since last spring from a PCA weekend at Road America, and I finally got around to sending it in to Blackstone, where I try to send a sample after most oil changes.
The specs for this oil:
-Mobil 1 0w40; total of 2000 miles; apx. 350 track miles (Brand new oil before track)
-30/70 antifreeze:water, with RP Purple Ice
-80* Ambient temps
-30 minute track sessions; sustaining 285* oil temp for 3 laps followed by 1 cool down lap, then repeat. Peak oil temp of 290 in a few runs.
-335 with 45k miles FBO; no meth, no extra oil cooler.
Overall the oil shows no signs of fatigue or degradation from heat; which has me rather surprised. Good nonetheless
Since this event last spring, I've added an AR Oil cooler (which did practically nothing to help temps) and also meth. Now without meth, temps stay down at roughly 275; but with meth it stays down to 265*
by MDM Enterprises
, on Flickr