Oil pressure gauges- mechanical vs. electrical

[xeroinfinity]

I was wondering what others thought about these two different types of gauges.

So my Poll question is,
Which of the two give the most accurate reading?

Reason being that I am thinking about installing one in my Grand Ams.
The electrical would be the easiest since thiers already a sensor that I could tap in too.

[SpinnerCee]

They're both pretty accurate to at least a pound -- the real difference is the electrical sending uint -- good ones can be more accurate than the mechanical unit's plumbing.

If you use an existing sending unit, you'll have to make sure that it is compatable with the gauge you intend to use, and then, it will only be as accurate as the original gauge was -- if you are adding a gauge to what was an idiot light, you'll have to replace the old sending unit because it is only a go or no-go sensor (it only turns on and off).

The preferential difference electrical vs mechanical has to do with the fact that electrical gauges do not have the 270 degree sweep of mechanical gauges (electrical gauges typically sweep only 45 degrees), and this is where the "accuracy" is questioned (it's really more a "resolution" issue) -- gauge manufacturers realized this and now you can find 270 deg. sweep electrical gauges.

[xeroinfinity]

I saw some electrics with the full sweep, thats not a big deal realy.

My GA's dont have a factory gauge for oil pressure , but does have a sending unit by the oil fitler. I'll probly go with the electric, just replace the old sending unit.

I hate running those lines for the mechanical ones.

[MrPbody]

I agree, with a stockish streeter, the electric would be easier. The guage companies that supply them also supply the correct senders. Without the CORRECT sender, you're shootin' in the dark... The stock sender won't be accurate with an aftermarket guage.

For higher level cars and race cars, mechanical is the only way to go. The upside is there won't be any electrical gremlins giving you false readings. The downside is, oil pressure IN THE COCKPIT. This isn't generally a problem, but it DOES happen. If the line breaks, oil is sprayed around.

High quality mechancal guages are most accurate. That's what you'll see in any "pro level" racer. They favor the "liquid-filled", as well.

FWIW

Jim

[xeroinfinity]

thankx for the reply MrPbody.

I've had a couple of those mechanicals spring leaks,
what a mess

The last one I had in a Nova.
I put a rubber vacum line on the oil line to keep it from getting nicked or creating such a mess if it did leak.

The electric autometer gauge I was looking at does come with the sending unit.

[skibum1111]

I prefer electric gauges. On my scuba regulator, mechanical pressure gauges (the one that tells you how much air is left in your tank and thus very accurate) give you a reading thats plus or minus 500 lbs. My dive computer gives a reading that is plus or minus 5 lbs. Take your pick.