temperature guage

I suppose that "gauge" is better than the goofy little light in my 2014, but given that lack of scale, I am betting it's still a classic modern non-linear dummy gauge that jumps up to normal and only goes into the red once you're already overheated.

I'm always amazed that manufacturers have the sensor data available (as stated, you can get it with OBD reader), but refuse to present it in any truly useful form. I almost pulled the trigger on an aftermarket gauge for my CX-5 right after I bought it, but decided I had better things to do. :D

The myth that cars have dummy temperature gauges needs to die.
Cars are equipped with a fancy piece of plastic with some wax inside called a thermostat :) This thermostat helps the engine warm up quickly and keeps the engine at the correct temperature once it gets there.
 
The myth that cars have dummy temperature gauges needs to die.
Cars are equipped with a fancy piece of plastic with some wax inside called a thermostat :) This thermostat helps the engine warm up quickly and keeps the engine at the correct temperature once it gets there.

Not a myth. Tested it on my daughters '04 Mazda 6
 
Not a myth. Tested it on my daughters '04 Mazda 6

how did you test it?
I've checked to OBD2 ECT temperature on several cars and with the exception of extreme driving conditions (110F uphill stop and go) the ECT never moved, and when it did it was instantly visible on the analog temp gauge of the RAV4.
 
I suppose that "gauge" is better than the goofy little light in my 2014, but given that lack of scale, I am betting it's still a classic modern non-linear dummy gauge that jumps up to normal and only goes into the red once you're already overheated.

I'm always amazed that manufacturers have the sensor data available (as stated, you can get it with OBD reader), but refuse to present it in any truly useful form. I almost pulled the trigger on an aftermarket gauge for my CX-5 right after I bought it, but decided I had better things to do. :D
I can absolutely assure you that the gauge is accurate and climbs gradually to normal. You can also see the effects of crawling in traffic where it just nudges normal then drops to just under when travelling again. The blue and red lights are retained for back up and as an alternative if you are using the various other screens. I think the blue light is partly an advisory not to cane the engine when cold and as an indication of readiness for those cars with Istop. As a matter of interest, all 2017 Cx-5s are fitted with a radiator shutter to speed up warm up times and all diesels are fitted with a 1Kw PTC (Positive Temperature Coefficient) electric heater element inside the heater which assist the heater during warm up. This is because the diesel engines are very thermally efficient and take quite a long time to heat up. Most of the heat from combustion goes out through the exhaust.
 
I have no issues with having just the indicator and not a temperature gauge

Sent from my SM-G935F using Tapatalk
 
The myth that cars have dummy temperature gauges needs to die.
Cars are equipped with a fancy piece of plastic with some wax inside called a thermostat :) This thermostat helps the engine warm up quickly and keeps the engine at the correct temperature once it gets there.
Not a myth. Tested it on my daughters '04 Mazda 6
Agreed! The "mechanical" coolant temperature gauge in many vehicles is indeed just a non-linear idiot gauge. It has only 3 positions: low、normal、high, based on the same signal source as the one with temperature warning light. The coolant temperature gauge in my 2001.5 VW Passat is also been tested and verified as a non-linear idiot gauge.

BTW, the coolant temperature gauge, like fuel gauge, in 2017 CX-5 is not old-fashioned mechanical gauge, but a LCD graphic display. While the coolant gauge is a very welcome added feature, I still wish the gauge is not buried in pages of display with MPG gauge and many other informations.
 
I can absolutely assure you that the gauge is accurateand climbs gradually to normal

With all due respect, how would you know the gauge is accurate when the scale divisions aren't even divided equally?

There's no way to read this so-called gauge unless the indicator falls on a number. I defy anyone to tell me what the value is when the indicator is not on the numbers.

Since there are only three numbers, no matter how gradual you think the rise may be, I can guarantee you its not a calibrated gauge and could be easily replaced with three lights - cold, med, hot.

Would you accept a home thermometer that read 0, 98.6, 108? That's what Mazda has given us here. Nothing new.
 
The myth that cars have dummy temperature gauges needs to die.

You are correct that a properly functioning engine should maintain its temp within a normal range, so for most people this is not important. However, if you provide something that looks like a gauge it should have uniform divisions and be calibrated so that its useful. Without this, it's still a dummy gauge - not a myth, just useless.
 
With all due respect, how would you know the gauge is accurate when the scale divisions aren't even divided equally?

There's no way to read this so-called gauge unless the indicator falls on a number. I defy anyone to tell me what the value is when the indicator is not on the numbers.

Since there are only three numbers, no matter how gradual you think the rise may be, I can guarantee you its not a calibrated gauge and could be easily replaced with three lights - cold, med, hot.

Would you accept a home thermometer that read 0, 98.6, 108? That's what Mazda has given us here. Nothing new.

It's irrelevant. The gauge is calibrated to show the most important part of the range and the sensor is capable of measuring one degree increments as shown when reading from the OBD socket. Why does it have to be linear and just how many increments do you need? It just so happens that when considering engine temperature, "normal" is a lot nearer to boiling than it is to cold or ambient. The gauge is no different to an old analog scale showing normal in the middle. In your ideal gauge you would show (I have to use sensible metric units) cold could be 0 and normal would be 88 (thermostat opening temp) right over near 100 or boiling. It would look like this C---------------N---H. Mazda have done what manufacturers have always done, given us a sensibly calibrated and easy to read gauge. The fact that the gauge rises gradually and doesn't index forward in incremental steps shows that it is reading an accurate output from the temperature sensor and these days, they are very accurate considering their simplicity - maybe a range of 3 or 4 degrees C.
 
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It's irrelevant. The gauge is calibrated to show the most important part of the range and the sensor is capable of measuring one degree increments as shown when reading from the OBD socket. Why does it have to be linear and just how many increments do you need? It just so happens that when considering engine temperature, "normal" is a lot nearer to boiling than it is to cold or ambient. The gauge is no different to an old analog scale showing normal in the middle. In your ideal gauge you would show (I have to use sensible metric units) cold could be 0 and normal would be 88 (thermostat opening temp) right over near 100 or boiling. It would look like this C---------------N---H. Mazda have done what manufacturers have always done, given us a sensibly calibrated and easy to read gauge. The fact that the gauge rises gradually and doesn't index forward in incremental steps shows that it is reading an accurate output from the temperature sensor and these days, they are very accurate considering their simplicity - maybe a range of 3 or 4 degrees C.

A gauge with insufficient gradations to enable a VALUE reading, or with a scale without a known progression (doesn't have to be linear) is useless. Any freshman STEM major knows this to be true.
Actually it's worse than useless as it makes you think you're getting valuable data when you are not. Ask anyone who's posted on this board with a catastrophic overheating condition when the gauge still showed normal and see how happy they are with this nonsense.

Unfortunately, the information presented on our dashboards has gotten progressively less useful as auto makers feel there's nothing we should be doing with detailed info anyway. Just look at the total elimination of oil and ATF dipsticks under the hood by some manufacturers for a further example of this thinking. Just trust us! We'll turn on your check engine light if anything goes wrong and your dealer will handle it.

FWIW, My ideal gauge would just give me the single number from the computer I can poll through OBD while turning it yellow and red if higher than normal. You mention that capability but then settle for 3 numbers and call this gauge "sensibly calibrated'? (dunno)

Clearly you enjoy the gauge as provided, so I'm done here.

Enjoy your Mazda.
 
TempgaugeBoth.jpg


From https://forum.miata.net/vb/showthread.php?t=346897&page=2

One guy tested his car and found the gauge stayed in the center for 80 deg.
 
TempgaugeBoth.jpg


From https://forum.miata.net/vb/showthread.php?t=346897&page=2

One guy tested his car and found the gauge stayed in the center for 80 deg.
Yeah this coolant temperature gauge from a Miata further proves that many gauges are simply a idiot gauge. IMO Thaumaturge does have his point that a gauge with insufficient gradations to enable a value reading, or with a scale without a known progression like the coolant temperature gauge in 2017 CX-5 serves more for cosmetic purpose. It's still better than featuring only a couple of warning lights no matter if it's a simple idiot gauge or not.

Here's what it looks like. The car was just started so still reading cold.

attachment.php
 
So long as there is something to warn me when the temperature is in the critical zone, that's all that matters to me as I know not to drive when it's like this and to pull over.
 
Well according to professor Einstein, you need a gauge two feet in diameter with each individual degree clearly marked in a linear scale or you’re going to miss some very important information ;-)
 
Well according to professor Einstein, you need a gauge two feet in diameter with each individual degree clearly marked in a linear scale or you’re going to miss some very important information ;-)

Can we have that HUGE temp gauge projected up onto the windshield with the head-up display? (detect)
 
Should be easy to check if the new temp gauge on the 2017 CX-5 is still an idiot gauge or a true digital gauge. Just hook up an OBD2 reader and compare the values while driving.

I'm not a fan of the old temp gauge where it uses a light to say it is cold or overheating. Reason being, the blue light turns off once you pass 130 F. At that point, you're still nowhere close to 190 F, actually, you don't know what the real coolant temp is at that point. So how would you know if you can flog it already? I guess you can wait 5 minutes and assume it is safe to drive spiritedly then.
 
My temp gauge works its way slowly up to just below the 210 mark, and stays there. I will check next time I'm pulling my trailer and see if it creeps up any higher.
 
My temp gauge works its way slowly up to just below the 210 mark, and stays there. I will check next time I'm pulling my trailer and see if it creeps up any higher.

Towing is the big application where knowing the actual temp is pretty important. You may want to get one of the little ODB-II readers and pair it with something like the Torque Pro app so you can monitor your actual temp off the sensor in real time. Unfortunately on the CX-5 it seems there is no separate code for ATF temp like there is on other vehicles probably due to the way the trans cooler is designed.

Nonetheless, I would not depend on the dummy gauge in this car if I were towing frequently since my local Mazda tech confirmed these are some of the most fragile trans/TCs he's ever seen. Much has been written on this topic elsewhere here. I had to wait to buy AT fluid recently since they used up their stock on a tranny replacement. Overheating a tranny never leads to good things.

This thread gives you more of the details on the OBD-II readouts: https://www.mazdas247.com/forum/showthread.php?123859171-Any-Scangauge-users-confirm-AT-temp-is-picked-up
 
Yeah, I may get one of those. I was just wondering if it would actually move the needle up any on the gauge somewhere between the 210 and the next mark while pulling some extra weight.

I towed a lot with my 2014 CX5. Several times for pretty long distances with 2000 to 2500 lbs, shorter trips with 3000 lbs or a little more including trailer weight and never felt like the transmission was struggling. Sold it with 100,000 miles on it and it was running great!
 
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