I'm thinking about installing two guages on my 03 MCS to fit on the left and right of the tach (no nav in my car).

What are the two most useful gauges?

I'm leaning towards boost and oil pressure, but I'm also considering boot and water temp.

Voltage seems kinda useless to me, nice to have if it's already there, but I'm not going to spend money to put one it.

Oil Temp? (is this better to have than water temp?)

 

Between water or oil temperature, I vote for oil temp. It will tell you when the engine is warmed up (so you can take it easy before then).

 

I have the Boost and Water gauges from RogueMini. I love them. Top quality, relatively easy to install, and they look terrific - not to mention, they are competitvely priced, the ordering process is smooth, and they arrived in 2 days.

Highly recommend them

 

That is what I did

 

Boost for sure. Oil pressure is gonna be more useful unless you are runnning a high hp setup. You temp gauge is a poor mans substitute for the temp gauges, whether it be oil or coolant. Consider adding more info, before getting more detailed on any one thing. I currently run the Defi Blue Racers for oil pressure, temp and boost,I got from m at Rogue MINIs. Great setups.