This is slightly off, but mostly true.

While this is 100% true *any* mechanical pressure gauge, mechanical temperature gauges do not have the fluid you're measuring physically coming back into the car's cabin of the vehicle. What they have is a capillary tube that is generally rather large, that is charged with Ether gas under pressure, and then soldered on the end to seal it. The fluid heats up the bulb on the end which in-turn heats the ether causing it to expand and apply pressure to the gauge's internal mechanism/movement which moves the needle. Just keep in mind that while most mechanical temperature gauges have this capillary tubing insulated, it can only be done so much. Any other source of heat applied anywhere along that capillary tubing (from the bulb going into the vehicle) can cause the gauge to read inaccurately. Also, you must avoid sharp bends (especially at the gauge and buld ends) and keep bends minimal and smooth.

Mechanical pressures such as Oil, yes; you will have a physical line full of oil (and likely some air too, but it doesn't throw off your reading; pressure is pressure after all) running into the cabin of your vehicle. For this reason, unless this is a gutted race-only vehicle, I'd recommend going electric on any gauge monitoring liquid pressure, for air pressure, completely up to the driver/owner/installer IMO.



Personally, I run full-sweep electrics in all of my vehicles; no mechanical's anywhere. I don't like the mess, I don't like the lines, and I enjoy the ease of install + the extra features of an electric gauge. I enjoy knowing my peak boost, having warnings on all of the various gauges I run and also the Elite's offer several different color combinations that can be setup through under and over warnings, as well as a normal range too. They just work for me well.

Hopefully this helps clear up some details between the two.

 

You can log some of the electrical gauges with data aq systems.

 

No gauge is perfectly accurate. Especially a boost gauge, whether it is mechanical or electrical. I do like that you can data log some of the electrical gauges.

 

Anyone?

 

If you do any real track days with the car oil temp is KEY.