Mechanical vs. Electric

Hey guys i was just wondering if there is any functional difference between mechanical and electric gauges, such as mechanical or electric fuel pressure gauges. I am looking at gauges from autometer and i also need to install a kirban so i need a fuel pressure gauge to do that too. i was wondering if i can get a mechanical gauge and if it functions the same as an electric because i really dont know the difference. I was also looking at getting other mechanical gauges from autometer. let me know what you guys think. Thanks!

If you are talking about a gauge for use under the hood, only for diagnostic work, not a permanent fixture you can get a mechanical gauge. In a mechanical gauge, the fuel itself would put pressure on the mechanism that controls the read out. A mechanical oil pressure gauge would work the same way.

If you are wanting a gauge that installs inside the cabin of the car, you need the type of guage that has an isolator in the system to keep the gasoline from being in the car. The gas goes as far as the isolator which then send a signal (electrical) to the gauge in the car. You never want gas in the cabin of a car.

In general, an electrical gauge takes the signal - oil pressure or coolant temperature, and converts it to an electrical signal that gets sent to the gauge

Thanks Pete. So your saying that if i put gauges in my car im going to need electrical gauges for all? Or for, say boost gauge and maybe other gauges i can get away with a mechanical gauge?

Well you definitely want an isolated fuel pressure gauge if you are going to mount it in the car. I used a mechanical oil pressure gauge, but I replaced the cheap plastic tubing with copper tubing. Sunpro or one of those actually makes a separate copper tubing package. I got mine at AutoZone. I went with an electrical for coolant temp. Make sure to use the sender that comes with the gauge. See this for other installations tips; http://www.turbotbird.com/techinfo/PeteG...eG-Pod.htm

Like Pete said if the gauge for fuel pressure is mounted in the passenger area you need an electric gauge. Some say the same for oil pressure.

If cost is a factor the electric gauges are more expensive due to the use of the electric sending unit. Mechanical gauges are usually less money.

Remember, if the item you are measuring can harm you you need an electrical gauge (fuel pressure); if it won't harm you mechanical is OK (boost).