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Reading tire pressures from inside my house!

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I installed FoboTire today on all four wheels.

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This is an amazingly cool device and it make possible on-the fly readings of the pressures in each tire. In fact, I'm sitting in my house at the very moment taking readings of my Model S tire pressures, even thought the car is parked 100 feet away outside. FoboTire is a bluetooth device and comes with a smart phone app for IOS and Android. It took me about 10 minutes to install and set up. At $179.00 the peace of mind it provides is worth every penny and when I get low pressure tire warnings they'll be based on my own settings, not Tesla's. Best of all I'll know which tire is low without having to do the tire to tire shuffle required by Tesla's inadequate system.
 
What a fascinating modern world we live in.

If I may gently ask, however, is this - remarkable, yes - product one that is a solution looking for a problem? Or perhaps it really, truly could be useful if one lived in fear of someone deflating your tires on the sly: you could catch 'em in the act.

gotta get me some!
 
According to the user's manual, FOBO will alert when the tire pressure reaches 51 psi. With a cold temperatures of 45 psi, could 51 psi be a normal operating pressure when hot?

Quick calculation: if the pressure absolute pressure is 45+14.7 = 60 psia and an alarm pressure of 66 psia, with pressure proportional to absolute temperature, when the absolute temperature rises to 66/60 of the cold temperature, the tire will hit the alarm. If cold is 300K, then alarm will sound at 330K, meaning a rise of 30C or 54F. A hot tire could easily be that warm, it seems.

Do you see this as a problem?

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Here's another brand that specs 65 psi capacity. http://us.papagoinc.com/?page_id=1492 I don't know how good it is.
 
This looks very neat, where do you store the in car unit.

In the store space in my Evannex center console. It can be attached with Velcro pretty much anywhere.

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What a fascinating modern world we live in.

If I may gently ask, however, is this - remarkable, yes - product one that is a solution looking for a problem? Or perhaps it really, truly could be useful if one lived in fear of someone deflating your tires on the sly: you could catch 'em in the act.

gotta get me some!

I've had two instances where the Tesla system caused unnecessary problems. In both situations I had parked at the airport for a few days and found a low pressure tire warning when I returned from my travels. I then had to get out my pressure gauge and check each tire to determine which was triggering the warning, a real PIA, especially on cold evenings in the dark. With FoboTire I would have known which tire was the problem and the magnitude of the pressure shortfall.

Plus I'm a fanatic about tire pressure. I check tire pressures every week and make sure they're to spec -- that to prevent unnecessary tire wear and keep handling at max. FoboTire will save me a lot of time, and time is money.

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According to the user's manual, FOBO will alert when the tire pressure reaches 51 psi. With a cold temperatures of 45 psi, could 51 psi be a normal operating pressure when hot?

Quick calculation: if the pressure absolute pressure is 45+14.7 = 60 psia and an alarm pressure of 66 psia, with pressure proportional to absolute temperature, when the absolute temperature rises to 66/60 of the cold temperature, the tire will hit the alarm. If cold is 300K, then alarm will sound at 330K, meaning a rise of 30C or 54F. A hot tire could easily be that warm, it seems.

Do you see this as a problem?

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Here's another brand that specs 65 psi capacity. GoSafe TPMS 500BT | I don't know how good it is.


The minimum and maximum tire pressure warnings are user settable. I set my pressures at 44psi, with 51 max and 41 min, and its very cold here now. I don't think I'll exceed the 51 psi max. I don't think the tires heat up enough to add more than about 3psi, but as I can monitor this as I drive, I'll know very soon.
 
In the store space in my Evannex center console. It can be attached with Velcro pretty much anywhere.

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I've had two instances where the Tesla system caused unnecessary problems. In both situations I had parked at the airport for a few days and found a low pressure tire warning when I returned from my travels. I then had to get out my pressure gauge and check each tire to determine which was triggering the warning, a real PIA, especially on cold evenings in the dark. With FoboTire I would have known which tire was the problem and the magnitude of the pressure shortfall.

Plus I'm a fanatic about tire pressure. I check tire pressures every week and make sure they're to spec -- that to prevent unnecessary tire wear and keep handling at max. FoboTire will save me a lot of time, and time is money.

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The minimum and maximum tire pressure warnings are user settable. I set my pressures at 44psi, with 51 max and 41 min, and its very cold here now. I don't think I'll exceed the 51 psi max. I don't think the tires heat up enough to add more than about 3psi, but as I can monitor this as I drive, I'll know very soon.
Can you put it in the center consol and close the covers, it would be nice to know which tire is low.
 
FYI the tire pressures I'm reading inside the house are the last pressures when I left the car. The app remembers the pressures, but unless you're within Bluetooth range it does not update them.

Neat. I ordered a set. What do you think the accuracy is?

Will be checking that with an accurate gauge this weekend.

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Can you put it in the center consol and close the covers, it would be nice to know which tire is low.

Yes, that's what I do.

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Any impact on wheel balancing?

None, it's too light to make any difference.

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But no more American Flag valve caps. :eek:

I'll be finding a source for flag decals that I can place on top of the Fobo sensors. or maybe ones with the Tesla logo.

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On my 15 mile drive this morning the tires gained only 2 lbs of pressure. It was about 28 degrees outside when I started the drive. The Fobo also gives a read out of tire temperature. Mine were 28 degrees when I started and about 45 degrees when the drive ended.
 
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Comparing today's result to theory:

predicted change of pressure = (change in temp)/(absolute temp)*(absolute pressure)

= (45 - 28) / (460 + 28) * (45 + 15)
= 2.1 psi

Close enough. If the tires hit ~60F above ambient you'll reach 51 psi. It seems possible:

A Look Behind the Tire Hysteria - Column - Car Reviews - Car and Driver says "Typical tires experience a temperature increase of roughly 50 degrees after running on the highway for a half-hour."

That said, if it only happens rarely, and the warning isn't too annoying, it could be ignored.