What a tire guy told me about TPMS. True or false?

I didn't know about the TPMS. Anyways that was 10 years ago. It's too late to make claims for something happened 10 years ago.

 

But for some of us, this cost is greater than the value the system is providing.

I wish it did show us actual tire pressures, rather than a single go/no-go indication for the whole set. The current indication is inadequate for my tire pressure maintenance pattern.

Since my winter/summer switching usually means swapping wheel sets at home, without cracking any rubber off any rims, any battery change before I'm ready to throw the tires away will definitely mean additional cost.

 

It doesn't seem many factory systems display actual pressure readings, and likely won't give you a selection of pressure limits. I've heard systems will also give a warning when over a limit. In which case, I might have it warning me all the time.

 

I just rented a Chevy Malibu, and part of it's MFD was the tire pressures. It took me the entire trip to realize the "info" button on the steering wheel is what cycled through every little item. I never did figure out how to reset the darn TRIP A odometer before returning it. It wouldn't be too hard for Toyota to make it something you could access, but knowing where each particular sensor is, tire wise, might be a little more difficult. Although, one would imagine it could figure that out easily with a more flexible setup.

As much as I think this particular requirement is an excess item, in the long run it may be a cost savings item to a many drivers that do not check tire pressures regularly or know how to check them (there are many folks that don't, not surprisingly to me). I wish having mandated this, they would have gone a little further to make it easier for the consumer to find the pressures, initialize new sensors when needed, etc. In other words, make it consumer friendly, since the consumer is the ultimate one affected by it.

 

Generally, the direct measurement sensors are more accurate and I'm sure require less system integration and validation work to be done.

Thank you idiots with SUVs rolling them over.

It's interesting that the tire pressures Tesla recommends are significantly higher than the recommended Lotus Elise pressures (26F 29R for the A048 equipped sport pack models).

 

I have yet to fiddle with my CT's TPMS, but if I understand it correctly I can set the threshold to any reasonable number I want by first inflating the tyres a couple PSI above the desired number and deflating afterwards.

Daniel: Your intuition that the tyre guy was a bit of a goofball was no doubt correct for good reasons. My thoughts reading the arguments was that 1, absent GPS, distance is a calculation, not an independent variable; and 2, I'd guess that conclusions are being drawn by comparing the tyres to each other. Not only does this require a whole set of assumptions along the lines of "everything else being equal...", there is the obvious stickler that tyre circumference does not change linearly with pressure.

So while your guy misunderstood the general idea, his real downfall was thinking that indirect TPMS is as sensitive as our current systems.

 

I replaced the tires on 2 of my vehicles equiped with tpms . Each rim requiored what they called a rebulid kit and it was $5 to $7 for each. They said if you have any problems with them bring the car back, they are guaranteed the life of the tires. This was a national tire shop not sure what toyota would charge for this. I had both cars for 2 years after and had no problems.

 

The rebuild kit is just a bunch of rubber O rings that they replace.

 

"if all the tires are low it would look like normal to the ABS."

Agree, also it wouldn't know if it's getting more revs due to tire pressure or tire tread wear so I'm concluding the guy was talking out of his rear end.

EDIT: scanned some posts in this thread, color me surprised...

 

Raising the pressure will lower the rolling resistance as the sidewalls will flex less. There is also improved handling and rougher ride trade offs, but Tesla surely went with the higher pressures for increased range ratings.

 

That's a good share of the reason for higher pressure.

Tesla = 2723 lbs (Tesla spec sheet)
Elise = 1832 to 2032lb depending on model (Lotus website)

They both list the same size Yokohama Advan Neova AD07 tires.

 

Indirect TPMS works with ABS and (usually) can only detect that one tire is low, but not which tire it is.

Direct TPMS does NOT use ABS, but rather works via RF link with ECU, and can detect & display which tire (of up to 5) is low..