Check Your Spare Tire Pressure

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Occupied Calif.
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2019 CX 5 GT-R
I do agree with you that it’d be more dangerous to change the tire TWICE on freeway shoulder especially with 18 wheelers passing by! Been there and done that when I had blow-out from my Michelin tire twice on my previous VW Vanagon! I’d just put the compact spare on to wherever the flat tire is, front or rear, and drive the car way with caution and under 55 mph to the nearest tire repair shop.
Or at least drive it to the closest, safe place to change it, like a paved, level parking lot or similar spot.
 

sugob

2021 CX-5 Signature (US)
One thing I was disappointed about was the CX-5 not having a page on the instrument cluster showing individual tire pressures [each as a figure in psi]. Was useful when I had a slow flat on a rental car as could see the figure descending until it got to ~22/23 psi and then the warning coming on [showing the correct tire that was low]. May also be useful to easily see when a tire is down a few psi to prompt further investigation.

Though I don't think the rental showed the psi on the spare.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
One thing I was disappointed about was the CX-5 not having a page on the instrument cluster showing individual tire pressures [each as a figure in psi]. Was useful when I had a slow flat on a rental car as could see the figure descending until it got to ~22/23 psi and then the warning coming on [showing the correct tire that was low]. May also be useful to easily see when a tire is down a few psi to prompt further investigation.

Though I don't think the rental showed the psi on the spare.
Yep, something like this found on Nissan Rogue would be nice!

4A527BDE-A743-4BE5-95CA-1EF9F53D0AEC.jpeg
 

sugob

2021 CX-5 Signature (US)
Yep, something like this found on Nissan Rogue would be nice!

View attachment 297687
Yea, that's nice especially as it shows the recommended numbers [if I'm correctly assuming that's what the blue 35 vals are] and also the units 'psi'. I believe the car system [TPMS] already knows the pressure in each tyre [inorder for it to know when to put the low pressure indicator light on] so it doesn't seem like a difficult/expensive feature to add in future years [more surprising it isn't there already considering I've had it in a few cheapish rentals - in my case I think it was a ford ecosport which was neither sporty nor economical!]
Anyway, what's with the pressures showing - 20 & 15?
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
⋯ Anyway, what's with the pressures showing - 20 & 15?
Yes, 35’s in blue are recommended tire pressure (front and rear, only for factory tires). 20 in amber, and 15 in red simply show this psi (or kPa in metric) tire pressure display has color warning capability (amber - warning、red - caution etc.) on purpose.
 
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2016.5 CX-5 GT AWD titanium/black 2016 Miata Club ST MT white
One thing I was disappointed about was the CX-5 not having a page on the instrument cluster showing individual tire pressures [each as a figure in psi]. Was useful when I had a slow flat on a rental car as could see the figure descending until it got to ~22/23 psi and then the warning coming on [showing the correct tire that was low]. May also be useful to easily see when a tire is down a few psi to prompt further investigation.

Though I don't think the rental showed the psi on the spare.
Not all TPM systems have individual pressure monitors in each wheel. If you don't have this you don't get a readout for each tire/wheel.

There are two types of TPM systems. The above and the type that uses the vehicles ABS system to determine if a tire has low pressure, as compared to the other tires in the system. The ABS type only knows if a tire is low by comparing the speed at which it rotates (an underinflated tire is smaller in diameter than properly inflated tire and therefor rotates faster) to the other tires and if one tire is rotating at a different rate than the others it sets an error code and this gets displayed. The system doesn't tell you which tire is low only that one, or more, is.
 
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2017 Mazda 6 Sport
The 2019+ Mazda 3/CX30 have individual tire pressures. It will make it to the rest of the line as the models get their redesigns.
 

sugob

2021 CX-5 Signature (US)
Not all TPM systems have individual pressure monitors in each wheel. If you don't have this you don't get a readout for each tire/wheel.

There are two types of TPM systems. The above and the type that uses the vehicles ABS system to determine if a tire has low pressure, as compared to the other tires in the system. The ABS type only knows if a tire is low by comparing the speed at which it rotates (an underinflated tire is smaller in diameter than properly inflated tire and therefor rotates faster) to the other tires and if one tire is rotating at a different rate than the others it sets an error code and this gets displayed. The system doesn't tell you which tire is low only that one, or more, is.
Interesting, thou the ABS method doesn't seem that good e.g. if all tires are going flat [& won't know at engine start until you move]
The manual for my CX-5 2021 says [page 4.255 - over 3 pages long on TPMS]
"The tire pressure sensors installed on each wheel send tire pressure data by radio signal to the receiver unit in the vehicle"
This indicates the TPMS sensor is on the 'wheel' and not the tire - I thought the sensor is in the stem of each tire valve?
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Interesting, thou the ABS method doesn't seem that good e.g. if all tires are going flat [& won't know at engine start until you move]
Yes using the ABS sensors for TPMS does have drawbacks like you said, but the big advantage is the lower cost by utilizing existing sensors. And all gen-1 CX-5’s use this ABS sensor TPMS.

The manual for my CX-5 2021 says [page 4.255 - over 3 pages long on TPMS]
"The tire pressure sensors installed on each wheel send tire pressure data by radio signal to the receiver unit in the vehicle"
This indicates the TPMS sensor is on the 'wheel' and not the tire - I thought the sensor is in the stem of each tire valve?
The dedicated tire pressure and temperature sensor used in all gen-2 CX-5’s is a part of valve stem like CarpeDiem stated. But the complaint here is Mazda has wasted the function of dedicated and expensive TMPS sensors and doesn’t provide more information available from the sensor. A direct read tire pressure display on each tire is easy to implement with those dedicated TPMS sensors which will be much helpful to the car owners such as the one found on the Nissan Rogue:

121EB5F9-803D-4A74-B7CB-5829EC432985.jpeg
 
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2016.5 CX-5 GT AWD titanium/black 2016 Miata Club ST MT white
Interesting, thou the ABS method doesn't seem that good e.g. if all tires are going flat [& won't know at engine start until you move]
The manual for my CX-5 2021 says [page 4.255 - over 3 pages long on TPMS]
"The tire pressure sensors installed on each wheel send tire pressure data by radio signal to the receiver unit in the vehicle"
This indicates the TPMS sensor is on the 'wheel' and not the tire - I thought the sensor is in the stem of each tire valve?

What CarpeDiem said above. That's for systems with individual monitors in each wheel. These systems are superior in that they show what's going on with each wheel/tire combo.

This system mentioned above does have it's drawbacks as compared to the ABS based system. The first being those monitors take batteries. Batteries that will need to be replaced at some point. Some of these monitors are designed so that the batteries can be replaced, with the tires off of course. Others don't have conveniently replicable batteries and the entire sensor has to be replaced. Which means that the sensor will have to be 'mated' with the car's system. Might need the dealer for this and it certainly won't be free.

The other issue with the in wheel/tire sensors is when it's time for new tires and if you're unlucky enough to get a knucklehead working on your car who isn't paying attention to (or doesn't know) what he's doing. The knucklehead breaks your sensor(s) while removing/installing your tires and then what? Most likely the knucklehead isn't going to fess up when he makes this mistake and you won't know that he screwed the pooch until you take your car home and get an error from the system on the way.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
The Mazda 3/CX-30 show individual tire pressure. It will be coming to the rest of the line soon
This’s a page of owner’s manual from 2020 Mazda CX-30. If the future CX-5 is going to feature a direct read tire pressure display it should be similar. This direct read tire pressure display is long overdue for CX-5 with introduction to new TPMS since 2017 MY. Just hope the display has recommended tire pressure and is as colorful as Nissan’s.

D9E3BC9C-8BF7-425A-BF89-365DC464D88E.jpeg
 
Last edited:
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2021 CX-5T AWD CE
Just to clarify a few things....

TPMS sensors in the wheel are typically on the inside of the wheel but integral with the valve stem. They have non-replaceable lithium batteries which should last 5-10 years. For most, they should last between tire changes and tire shops will always recommend they be replaced with new tires. I recall the cost of the sensors (with built in batteries) was about $10 each. There is a reset procedure to pair them with the car but tire shops have all the equipment needed... you don’t have to go to the dealer. Ham-fisted tire techs do occasionally break one when dismounting a tire (I.e., to fix a puncture) but shouldn’t if they have an up-to-date tire machine and proper technique. Go to one of the major chains like Discount Tire and you should be fine.

I’m also disappointed that there is no direct readout of tire pressure on my 2021, either on the dash or with the MyMazda app. It’s a chintzy omission.

- Mark
 

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