The Prius c has no engine temperature gauge, why is that?

Most gauges in a Prius are 'eco' gauges, not 'car guy' gauges. I use a scangauge II to get RPM, voltage, water temp and under hood air temp. The Scangauge II has about 100 choices, those are mine.

PriusChat Shop : ScanGauge II Scan Tool + Digital Gauges + Trip Computers [ScanGaugeII] - $159.95

 

Modern automobiles are pretty darn reliable, an engine(coolant) temperature gauge would just add clutter. My old(2008) Honda Fit just had a blue light under the fuel gauge that came on at startup for a minute or so, indicating a cold engine so take it easy, and according to the manual, a red light would come on indicating an overheating engine(never ever saw that one, right up to 198,000km when i sold it). This is the trend and it seems most cars in the past few years go for the minimalist instrument panel approach, which is just fine by me.
The only place i see water temp, oil temp, oil pressure gauges, etc, these days is in trucks or other machines designed for towing, severe service, race cars and the like.

 

I have the coolant temp on the ScanGuage only because of the car's changing behaviour during the warmup stages (and it's only really useful with a digital display). Once it gets up to full operating temperature it rarely moves except in cold conditions, in which case it may drop when the ICE is not operating. Any other car I've driven sees the temp guage climb to operating temperature and stay there. It would only move if something has gone wrong, in which case the relevant indicator light would come on anyway.

 

In the Winter, the really nice thing about a temperature gauge is that you don't need to turn on the fan on your heater too soon as to have it blow cold air on you.

Consider yourself lucky.

 

Does the Prius C have a coolant temperature gauge? Good idea: Coolant temperature is useful info, one of the gauges I miss on our (regular) Prius.

 

No. A ScanGauge II (or other OBD reader) can read this information via the OBD II port however.

 

Why is that?
Money.

The same reason why the G3 doesn't "need" extended visors...sound deadening material in the doors...a proper seat....etc.

You're PAYING for the drive-train and for a platform that gets 50-something miles to the gallon.

 

Does the 'temperature gauge' in my old Subaru qualify as a real temperature gauge, when the entire temperature span from 150F to 210F is condensed to a single needle position?

The external OBDII reader (I use ScanGauge-II) is much more informative even for that old car.

 

If you set the temp on auto, the fan will not go on until the water temp is warm enough. At least that is what mine does

 

Yep, just like Vernon said

 

The engine oil temperature is more relevant if you need something to monitor.

Based on the warm up patterns of our other cars, I drive lightly for about 5 kms before I give it the beans