i noticed that recently. but i have been using the same oil. what has changed was the oil filter i was running. i have to use a certain filter due to the sandwich adapter plate that's connected to my oil cooler. the co. i was buying them from recently changed the filter (different part #) i think it no longer has an anti-drain back valve. i can restart the motor within a few minutes of turning it off and it registers on the gauge immediately. but if i start it cold (in the morning) or after a few hours parked, it takes a few seconds to show on the oil gauge.

 

I am running 10W40 redline. The oil gets pretty hot on the track. On a hot day 100deg, I was getting to 240deg.

I am going to install underbelly pen to trap the air in and improve air routing to my oil cooler (mounted in front the radiator on top of intercooler. I am planning to route air dust to it.

I would love to know if you guys think it's ok to switch to other brands than Redline