faisalk

what is the difference between electrical and mechanical gauges?

rynberg

been answered many times:

mechanical -- (boost for example) you actually run vacuum tubing to the gauge, in other words, the sensor is at the gauge itself

electrical -- sensor located at point of interest (boost nipple, oil line, fuel line, etc), only an electrical wire is run to the gauge

I think electrical is far superior, especially for some of the more potentially dangerous gauges such as oil or fuel pressure (!).

SanJoRX7

Agreed. In addition, electronic gauges tend to be more expensive due to the additional "stuff" that's in them. I tend to believe (might be wrong, but let me live my fantasy) that electronic gauges are of higher quality and are prone to being more accurate. In the case of the boost gauge, the less vacuum tubing you're running to the sensor, the more accurate your reading, since tubing tends to expand/contract with pressure, temperature and age.

I second the notion that ti's probably safer too, but my other reason for liking the electronic stuff is that since you're only running a wire through the firewall, if it breaks, you just replace it. Vacuum tubing might be a little more difficult to diagnose a leak in, and over time, you will definitely see that hose degrade, regardless of how good it was when you put it in.

Spring for the electronic stuff, it's trick!

maxpesce

Electonic Guages are actually CHEAPER to make - the GUAGE is just a calibrated OHM Meter and the senders are just pressure or temprature sensitive variable resistors Most Mechanical guages use a Bordoun Tube type mechansim (basicaly a spiral tube that expands w/ pressure changes) and a capillary tube to transmit the pressure change from the working fluid to the guage Mech TEMP guages use a SEALED BULB full full of a liquid that expands/contracts w/temprature changes thus imparting coresponding PRESSURE changes in the Guage.