Milwaukee 12:1 Infrared Temp Gun Review 

I really don't know how it would perform with oil. Plus, it would only be reading the surface temperature, not the temperature at any depth.

How to switch it off and can you get both F° and C° on screen ​@DoresoomReviews

There's no way to calibrate it, it comes from the factory pre-set. If you need one that has a calibration certificate included, they sell the identical 2268-20NST that comes with a certificate for 2-3X the price.