i had absolutely no prob with my mech gauge
as long as ur not retarded, then u shouldnt have a prob with a mech. just use the copper line or braided line, the teflon i dont trust

 

I've been running a mecanical 0-100psi oil pressure gauge in my '7 for a good long while. As long as you don't screw up running the line, there is no problem. I prefer mechanical gauges because they keep working when the car is shut down (this is more important when it comes to oil and coolant temp.)

If your Civic goes over 100psi, you have serious problems.