What's the difference between mechanical guage and electrical guage, which is better.

 

Mechanical- Has a pressure line, or feed line from the system running to it to push the needle on the gauge. Has possibility of leaking on you while you are driving. Provides more hoses and lines that you need to figure out.

Electrical- Has sensors, and wires that can easily be shrink wrapped, and noted for quick diagnosis. Does not have possibility of leaking 190 degree coolant or oil on you. Does not need random hoses or lines running around.

My choice would be electrical gauges, just make sure you get the right unit for the stock sensor, and then replace the sensor with a new OEM one. Dont want good gauges and bad sensors.

 

Your not supposed to be using the stock sensors. All the electric gauges should come with sensors, solenoid, and a gauge. They both do the job and it's a matter of preference.

 

On the other side of the coin, mechanical gauges don't require electrical senders that can go bad.
While temp sensors rarely go bad, it is much more common on pressure sensors. A new aftermarket one should be fine for several years, though.

 

My opinion is that electrical gauges are several times "better" then mechanical gauges.

Why? Several reasons...

They are far easier to install as you can just run wires in the harness instead of tubes and capillaries around the engine bay.

Electrical gauges can allow useful functions like data logging, peak and hold, etc. that are difficult if not impossible to get via mechanical gauges.

You don't have plumbing carrying hot pressurized fluids into the cabin area. For me, this is the most important.

Also it seems that when using the fittings that come with mechanical gauges, they ALWAYS seem to leak after a few years. I can't count the number of times I've worked on a car where underneath the dash is soaked in oil because of some stupid gauge...

 

^^Dont you just hate that?

Had one leak on my face, just after the engine had been warmed up. It was on my grandmothers old 300D turbo deisel mercedes. That crap was hot.