[Jasmine]

I never would have thought to even look at the voltage. Considering this post I watched mine today. It was 14 (I'm not sure of the decimal) right after starting this morning. I drove it 5 miles into town and let it set for a couple hours while I did some work. When I restarted it was showing 13ish. It's never given me a problem, even in severe cold (-35F). Today was more typical winter, +8F. Hardly anything to stress it other than sitting overnight. The alternator probably didn't have to work very hard.

Most of the cars I've had that even had a gauge didn't give you quantity. As long as it stayed slightly to the charge side I was happy and so was the vehicle. Ours is a 12V system -- that would be the center point of a conventional gauge -- so anything over that means it's charging. A lot or a little doesn't matter to me as long as it starts in the morning.

 

[Jasmine]

Anymore we are lucky to have either as the manufacturers know most Americans (I can't testify regarding other country's citizens) don't even have a clue to look at either type of guage much less know what the data means.
. . .
Most voltameters show numbers.

So where are the numbers on my oil temperature gauge? If ever there was a useless invention!

Sometimes it's difficult to find a practical use for a gauge. Maybe they should put detailed gradients on the oil temperature gauge and measure it in some obscure scale (like Rankine) that would mean nothing to the average driver.

 

[Jasmine]

The oil temperature only has an indicator.

That's like the TV weatherman saying, "It will be warm a couple days this week and cool on some others. Probably a fair amount of snow sometime before the weekend." I think George Carlin did a spoof on this, "The weather for tonight is dark followed by increasing light toward morning." That's about how useful a temperature gauge is without numbers.