Need for RPM and engine coolant temperature display on a Prius

I went with the Prius so I could stop worrying about that stuff

 

A Scangauge solves that problem without having to do anything to the car. Mine mounts with velcro on top of the steering "shaft". Plus you can reset codes if you leave a gas cap loose or such. And you can read codes, and you can watch esoteric stuff such as battery current.

 

This has been addressed in other threads. What you need is an ELM327 ODB II to WiFi interface and a suitable smartphone and app.

With this you will have ICE, MG1, and MG2 RPMs, coolant temperature, and many other bits of data that can even be exported to a spreadsheet. I haven't tried it but it supposedly will allow you to change several "dealer only" parameters, such as the reverse beep.

 

My Scangauge II routinely monitors RPM, DC Voltage, Engine water temp, and Engine air temp. There are over 100 gauges possible, you can display 4 at a time.
ScanGauge II ODB Scan Tool + Digital Gauges + Trip Computers - PriusChat Shop
Toyota/Lexus/Scion Specific : Linear Logic : Home of the ScanGauge

(My Gen2 Prius had issues when the Outside air temp was over 100, Engine air temp climbed alarmingly. I have not been able to reproduce this in my v. My Gen2 charged at 13.8volts while the v charges at 14.4volts)

In other threads, folks worry about 'hackers' taking over the OBDII bus and altering the operation of their Prius. One of the reasons it is not a concern is that engine management and infotainment are separate systems. I hope that on further thought, you want the engine management bus to NOT have bluetooth, 4G wireless or wifi interfaces. One reason I prefer the wired scangauge is that it is NOT wireless.

 

I' curious why you think you need this? Modern cars don't have to wory about these old-school tech issues anymore.

 

The answer is simple:

Knowledge = Power

- Wil

 

Or just more crap to think about....

 

Well, I forgot to add "…plus the experience to be able to differentiate the useful from the useless!"

 

Cheap Android smartphone, ELM327 OBD2 bluetooth adapter from ebay, and the Torque app from Google Play is all that you will need.

 

A few years back, I was driving my daughter-in-law's Pontiac Sunfire up to Costco for a road hazard tire repair, caught myself muttering: "even this piece of crap has tach and coolant temp".

Yeah: plus one on ScanGuageII. RPM is kinda nice, primarily to know for sure the engine is on or not. Coolant temp is invaluable.

 

In hindsight I agree with the coolant temp gauge. Not for the reason listed originally but for fuel efficiency reasons. Helps to know what stage you are in.

 

X2

 

my dodge dakota has a tach. why?

 

So you can ask the question?.................

 

I could never understand why a car with automatic transmission is outfitted with a tac.

 

exactly. if the prius had a tach, it would be interesting for a few days to see where it's operating at, then i'd never look at it again. same with a temp gauge.

 

The "tach" on my ScanGaugeII continues to hold my interest, when I've got it on. Interesting to see when the engine's actually off, versus sitting around 900 (idling?) when driving EV at highway speeds. Funny though, both the dash and ScanGuage agree the car's not consuming any gas in the latter case.

Apart from that RPM does seem to be "idle" interest, haha. And with ScanGuageII "gauges" being limited, RPM got bumped recently when I decided to monitor hybrid battery temps via an XGauge (programmable additional gauges on the ScanGuage).

 

(I drive a level highway* at constant speed, the variances in MPG are wind direction and speed, outside temperature, and wet roadways. If your commute is not as smooth, my results will not be your results)

When my v is going 62 MPH and the RPM is under 1700 I am getting 55 MPG
Under 1800 is better than 50 MPG
Over 2200 is under 45 MPG
For me, MPG while cruising is very related to RPM

992 is the idle when no spark is added

Even after 50 miles, RPMs tend to be getting lower and MPGs tend to be going up, both very slowly by then.

* It gains 100 feet in 156 miles, there are surface bumps but it is really very flat with long straights that allow me time to look at gauges. Feel free to enter Eden MS and Walls MS in your map program, use US 61, US 49, and US 49E

 

You might want to check out this thread the guy is using 3 scangauges to moniter everything about his car.