It could help you diagnose a weak battery or alternator. It can also help determine when you've added too many electronics and need to upgrade your electrical system.

Pretty much all gauges have a use, but there isn't always a need for them. I mean, most Evo owners don't really need an altimeter, but i wouldn't doubt some professional race teams use something similar to tune for higher altitiude tracks.

 

I have a LC-1 wide band. other than that, IDK