We just picked up our long-awaited Prius yesterday after 13 months. I am loving it so much already. But I did not see a coolant temperature gauge, only a warning light; please tell me it's there...
Yeah I dearly miss a coolant temp; but Toyota in their wisdom… have you had a previous Gen? Far as I know they’ve never had one.
It is there ... internally, which you can read with an aftermarket OBD-II-port monitor. Not as dashboard gauge. Neither of my past Prii had a dashboard temperature gauge either, but a ScanGauge-II plugged into the OBD-II port could should temperatures of lots of things besides just engine coolant. Many better aftermarket choices exist now. It was that ScanGauge that revealed to me that the temperature gauge on my '97 Subaru was lying. Or rather, engaging in 'customer expectation management', not budging a hair while the coolant temperature swung from 145F to something over 210F. Since then, I've had no use for analog 'gauges' programmed hide that swing, preferring instead a digital readout through the OBD port.
Even though I never had any of my cars over heated over the last 40 years, last week my mom asked me to take her car out for a spin and see if anything is wrong. We went to eat at a restaurant and when I tried to start the car, it didn't start. Called the auto club and jumped the car. Halfway from her home, the engine warning light came on! Her coolant temperature went into the red zone! Luckily, it came back down but went up and down like a yoyo...That's why I would rather have a gauge just like the gas meter.
When my mid-'80s car became old (>15 years), it yo-yoed. But that '97 didn't yo-yo, staying rock solid at a single point, except on a couple extreme heat events where it rose but didn't overheat. But then a ScanGauge revealed that it really did vary considerably in ordinary driving, especially when hypermiling, but within the temperature range that Subaru had collapsed to a single point on the gauge. So the "perfectly stable" temperature shown on the gauge was fake, hiding considerable excursions within a set but very wide range. Part of "customer expectation management". If you care about temperatures, get an add-on OBD-port device that will digitally read out temperatures of not just the engine coolant, but also the separate inverter coolant, MG1, MG2, HV battery, and likely a few other items. Possibly even a cat converter temperature?
I have used a P10 for years. The biggest benefit is observing the thermal cycling caused by stop and go traffic and long “idles”. The temperature has a lower alarm setpoint than factory and the mph is accurate with a high speed alarm for freeways.
As fuzzy1 experienced, many temp gauges on the dash aren't really gauges. They are just cold, warm, hot indicators. You won't see any fluctuating on them. The ScangaugeIII is now out. » ScanGauge III
