Is there a method to measure oil temperature easily?

 

Sure, you have to buy a oil temperature gauge, I have the Defi D mounted in an A pillar mount and an oil filter sandwich plate to go in between the oil filter and where the oil filter screws onto the engine. Install the sensor there, connect the wires and you are reading your oil temperature! most vendors carry the Defi D gauges, the oil filter sandwich plate you will have to pick up at japanparts.com.