Need for RPM and engine coolant temperature display on a Prius

Since I set one of the 8 sub-gauges (I have 2 SC-IIs) to monitor the ICE power (HP) (advice from Hobbit @ recent 2GoB4), I've noticed I get a much better idea of just how hard the ICE is working, and a better idea of when it's idling (<1000RPM) I also notice when there's hardly any power being generated, so I suppose at that point it's in RegenBraking mode. I'm impressed with the ScanGauge, and the company which makes it (Linear Logic). I bought my second SC-II from eBay but it had old firmware, and when I phoned LinearLogic, they sent me a new board (with the latest firmware) FREE (normally $25 for the upgrade), they didn't even charge me for the postage, and didn't require me to send the old one back! It took me all of 5 mins to swap the board (it's a bit fiddly, but I've done electronics tech work ever since I was 12) and now I have 2 Really Useful additions to The ChuggyPig! - Wil

 

Well, being an old shade tree mechanic back in the days when you had distributor caps, and rotors and timing lights to "tune-up" that car, I can see where a tachometer comes in handing. But with today's mostly computer operated engines, that don't need tuning and pretty much can go thousands of miles on a set of spark plugs, having a tac is truly unnecessary. Certainly there are some who feel it's importantto monitor rpm, but I just don't understand its purpose in this day and age of tech based ICEs. And basically, for me, the only set of letters I care about are "M" "P" & "G".

 

Oskar, I agree that rpm is one you can get by without.

But having coolant temperature or a hot/cold gauge is really helpful if your vehicle has a clogged radiator or if the electric thermo switch for the cooling fan fails.

I had a Honda Civic VX on which each failed at different times. The only way I knew there was a problem with the Honda each time was when the analog hot/cold gauge warned me.

By the time the coolant temperature warning light (idiot light, really) illuminates on the Prius, it's probably too late to do anything about the problem - whatever the cause. Goodbye head gasket.

 

Well, as already mentioned the ICE RPM is useful to note as (at least to me) it provides a definite indication that the ICE is actually not turning (see my previous comment about RegenBraking mode).

 

What about something like this:

 

These are a very nice graphics....

 

prius has a temp gauge, it's called an idiot light.

 

I qualify!

 

Good, and fair, points. But I put my trust in the build of the car and have to look at the repair/maintenance records of the Prius. According to 2014 stats Toyota has sold 6 million hybrids, and as of 2012 the Prius was the world's third best selling car. How many of those have had blown head gaskets as a result of overheating? Or other serious overheating problems that could have been detected by more sophisticated monitoring? Probably not that many.

Hey, I bought an OBDII WiFi interface scanner and EngineLink software and enjoy fiddling with it. But I really am not that interested in monitoring every single nuance of the car in the hopes of offsetting trouble. I have to have some faith in that my Prius is well built and will start and drive. Driving in today's traffic is hard enough as it is without having to worry if my car overheats, etc.

But each to his own. Music is my thing, so I can relate to how some want to dig deep into those things that interest them most.

 

There is no need. Living just 3 blocks from an uphill ramp to a 70 mph highway, none of my Prius have ever shown it to be necessary. That 12 winters in Minnesota. The system warms up so fast, you are already at a nice running temp.

With my plug-in over the following 2 years, I hit the ramp with the engine still off, since the extra battery power keeps the engine limited to 1500 rpm.

In short, it isn't necessary. It is nice to know though, since coolant temperature does inform you of heater status.

That's old news, from January.

As of 2 weeks ago, they hit the 7 million mark.

 

My Honda Civic was very reliable too until the radiator clogged, which can happen when a car is 18 years old, regardless of proper maintenance.

The oldest Gen 2's have recently celebrated their 11th b-days. Wait another 5 years and we'll see what starts failing on them. I believe that many will last that long and more. Probably not with the original traction battery though.

 

On steep mountain roads, a tachometer is useful for determining how far you can downshift without blowing the engine. I've often dropped two or more gears to keep at a safe speed - the engine is screaming like it's ready to start throwing pistons through the hood, but a quick glance at the tachometer assures that it's only mid-range and has another 2,000 RPM before redline. The alternative is to leave the transmission in "D" and risk overheating the brakes. However, I don't know of any reason that a tach would be of value in a Prius, except perhaps for troubleshooting some obscure problem with the drivetrain.

 

thanks, we have nothing of the sort out here.

 

UltraGauge OBDII Scan tool & Information Center - Another option - similar to the scangauge but a bit more versatile. Works well (although I don't know for sure how it does in a Prius.

UltraGauge OBDII Vehicle Gauge Availability Estimator

Definitely should give you temp, RPM, and voltage, though.

 

A cheap android tablet and an Elm 327 with Tourque app would give more information at far less cost. The information can be shown as, digital, analog gauge, or a mixture of the two, and as a graph. This along with gauge size choice, number, shape, and layout. The Scangauge is a useful piece of equipment, but is loosing ground to later, and cheaper technology .

John (Britprius)

 

I've owned a Scangauge II, Ultragauge, and bluetooth ELM327 adapter with Torque.

The Ultragauge is great and is the one I currently use in my Prius, but it is limited compared to the other two when used in a hybrid. It will show you all the regular car stuff, but you can't add gauges to show info about the hybrid specific stuff like the HV battery.

Torque is an amazing app and can be customized pretty much however you want. It can be a pain to set up your phone/tablet every time you get in the car, though, depending on how you have it set up. My ELM327 adapter seems to have died, but my use of the app was already diminishing because of having to set my phone up.

Scangauge II shares the gauge-adding ability of Torque with the plug it in and forget it of the Ultragauge. I prefer the Ultragauge's screen, both for readability and the ability to display more than 4 gauges. As mentioned, the customer service for the Scangauge is unmatched. Mine was causing issues with my Escape Hybrid I had at the time. Sent it in and they sent it back with a CAN only cable for free that fixed the issue. I left it with Escape when I sold it to my parents.

 

How do I see the gauge features on the scan gauge? Will the engine temp automatically display? I have one but haven’t used this part, just error code reading

 

Coolant temperature will be available out of the box, as it's one of the standard parameters. Same for RPM.

Other, more Prius-specific parameters have to be taught to a ScanGauge (by entering them as "XGAUGE"s, see the manual). There are lists of them on PriusChat.

Every so many years, doesn't the current phone become the former phone, while still being plenty powerful enough to run Torque?

 

Coolant temp on startup gives you a rough idea when you have a minimally warm engine. Coolant temp after driving awhile gives you a rough idea when the engine is fully warm. Oil temp is an even better indicator, but like many cars today, Prius lacks an oil temp sensor. Yes, an oil temp sensor and gauge can be installed aftermarket, as hotrodders often do, but it invalidates the warranty.

Traditionally, the dividing line between low and high rpm is 2,500 rpm. Putting high rpm on a cold engine increases engine wear. Seeing a tachometer tells you exactly how hard you're working the engine. Every time you double the rpm, you quadruple the pressure. The Hybrid System Indicator (HSI) approximates a tachometer, but it lacks precision and varies with coolant temp.