What gauges do you really need?

I'm trying to decide what gauges to add to my WRX. I have a scangauge reading the ECU output, which is able to provide four different parameters.

What I'd like to add is wideband, and fuel pressure for sure.

Pete. (l33t FS) said:

Mazdax605 said:

I prefer battery amps over battery volts, but I'm a DC power tech in the telecom industry. Knowing my amperage is often more useful than knowing the voltage. Both matter, but I like knowing if I'm charging or discharging more than the actual voltage.

When I was acquiring gauges for the GTI, I also bought an ammeter.  Even though everyone said they're a major pain in the ass because, unless you have a shunt type unit, all vehicle power has to go through it.

 

My rationale was, I have to completely rewire the car anyway.  And info is cool.  14v is 14v but if the ammeter is showing 50 amps of charge when I'm running with no accessories going, I know that the battery's pretty drained.

 

Interestingly, a lot of OEMs have amp clamps on one of the battery cables just for this purpose.

My 74 REPU uses a shunt type ammeter. Of course the battery lives in a box built into the right side of the truck bed. The shunt lives just behind the bench seat on the right side as well. It works pretty well and I wish more cars used ammeters rather than volt meters. 

In reply to Mazdax605 :

My stepdad's Town & Country ('76) had an ammeter.  Gauge was calibrated in C, neutral, and D.

Never looked into how it was wired in.

Need?  Water temp, big red light for oil pressure, voltmeter.  Maybe an hour meter to tell you when to change the rod bearings.  All the rest of it is just extras.  Circle track, add a tach somewhere with a memory.  It doesn't need to be in line of sight, but its nice to see whether you have the right gear.

I grew up when cars, and trucks, came with ammeters, if they had a gauge for electrical at all. I know that the the voltmeter will kinda tell ya the same info, I just prefer the ammeter way of achieving it. 'Course I hate pictograms in our cars, as well. But apparently, auto makers never cared what my opinions are.

And someone mentioned cars don't need a speedometer, or a tach; I guess cars don't need a lot of things, but I've gotten way to many speeding tickets not to have one or the other (doesn't matter which one). Assuming we are talking about a car driven on the street.

You don't NEED much - early Beetles didn't even have a fuel gauge until 1962.

On an endurance race car, I've come to the conclusion that I want a sequential shift light, a fuel gauge, and then a few super bright warning lights: Oil pressure low, coolant pressure low, coolant temp too high, charging system offline.  And a lap timer, of course.

What I want to know my RPM so I don't over-rev, but also to help manage fuel usage.   The fuel tank tells me how aggressive I should be (attack or economy mode).   Other than that, I don't want to have to think about whether the oil pressure was a 52 PSI and now it looks like it's only at 48 and should I be concerned?  Was the water temp really fluctuating between 215 & 210?  Etc..

Mostly because I am a driver with mechanical empathy, and I'll worry about the gauges and what it all means when I should be focussing on driving.

bludroptop said:

You don't NEED much - early Beetles didn't even have a fuel gauge until 1962.

This reminded me of the usefulness of a tach. I have a Class 11 ("Stock" Bug) off road car. The speedo was useless so we put a tach in that hole. Given that I had never driven a VW in a race and the engine is out back we figured it would be useful and it was. During the race we had a mix of all sorts of vehicles including loud trucks, loud buggies and other loud vehicles. It was nearly impossible to hear the engine. But a glance at the tach was pretty easy.