Well, since oil pressure is directly related to RPM i thought you could just have a needle that reacted to the RPM to simulate an oil gauge. Not that i mind how it works right now, but at first i got confused since i thought there would be other ways to simulate the oil pressure gauge without using a turbo.There's no such thing as oil pressure in AC, so you have to fake it with a turbo gauge. It's the most proper way to make it because it responds to RPM and throttle. How else?