Manual of electric oil pressure gauge?


Hey all,

I’m planning on installing a oil pressure gauge in my spec e30 and quickly ordered from Pegasus. I’m starting to think now that I should have bought an electrical gauge? Is this a bad idea running a mech gauge? Or is it a good reliable way to do it? I was thinking of pulling my stock oil press sending unit out and using that hole for the hose to run the gauge.

If a mech gauge is good, what more would I need other than the stuff that’s included with the gauge? I’m planning on doing some work on the car at a shop way out of town and it would be very productive to have everything I need.

Or just tell me I’m crazy and return it to get an electric gauge:)



we are very happy with our mechanical gauges. you need this fitting for doing the oil pressure gauge. very easy install.


Your mechanical 2 5/8th gauge has some charms. It’s easy to read it accurately because it’s big, and it’s full sweep (vs. 90deg sweep). It’s also more accurate then single wire gauges because there’s no chassis ground that can get iffy on you.

I used a gauge just like the one in your link, except black, for prob 5yrs and I liked it a lot better than the cheap 90deg sweep single wire versions.

Don’t use the hose that comes with the gauge. It would not be a legal set up to have that plastic hose come into the passenger compartment. Instead, buy some SS hose and put the right fittings on it. Preferably -3 or -4AN fittings, not NPT.

Here’s the best solution tho.

Configurable threshold alarms. You can set it to, for example, turn red at 25psi and flash red at 20psi. This tells you when your OP is starving in long left turns. You really do need some kind of oil pressure switch wired to a big warning light on your dash, so you either get a gauge like this, or you plumb in an oil pressure switch and wire in a big light.

While on the subject of pressure switches, don’t forget to put in a coolant pressure switch. Loss of coolant kills more of our engines then OP problems.

Data out. The Stack gauge will easily connect to your data logger.

Note that Autometer bought Stack a while back so Autometer sells their own line of gauges with the same features.

If you do end up using an electrical sensor, don’t thread it directly to the engine block using Andrew’s adapter. The heat and vibration will shorten it’s life. Instead, use Andrew’s adapter or a similar one that does -4AN in order to “remote” the sensor with 18" or so of SS hose to somewhere convenient to locate the sensor. You want to use AN adapters, instead of NPT adapters, as much as you can because they will happily allow themselves to be removed and replaced. NPT adapters aren’t designed for multiple R/R so they can start leaking on you if it’s not your lucky day.