Why didn’t Tesla use indirect (ABS) TPMS?

[chillaban]

I believe the "good" Indirect TPMS system, like the one used by VW/Audi on recent model years, is from one specific supplier that heavily patented their implementation. It is NHTSA approved and, as others said, sensitive to minute changes in pressure.

The biggest caveat IMO is that it's absolute garbage if you "reset" the system with improperly inflated tires. If you do that, then it'll never alert you to anything except nearly flat tires. And it's difficult to trust that customers will do that properly.

The direct TPMS systems are great since they tell you the exact tire pressure of each tire, even when at a standstill. You can use that to validate your tire inflation before you even drive off.


EDIT: The company is NIRA Dynamics AB: Nira Dynamics AB - Wikipedia

 

[zroger73]

ABS TPMS is no longer legal.

That's not correct. Most new automobiles still use indirect tire pressure monitoring systems in 2023. One of many examples: 2023 Honda Civic.

 

[heavyD]

That's not correct. Most new automobiles still use indirect tire pressure monitoring systems in 2023. One of many examples: 2023 Honda Civic.

Yeah Honda used to supply vehicles direct TPMS but to save money has gone to indirect on most of their new vehicles. Tesla has cut a lot of corners with these vehicles so we should be happy that they provide proper direct TPMS.

 

[zroger73]

Yeah Honda used to supply vehicles direct TPMS but to save money has gone to indirect on most of their new vehicles.

Honda's "cars" (HR-V, Civic, Accord, CR-V) use indirect TPMS and have for many years. Their "trucks" (Odyssey, Pilot, Ridgeline, and Passport) use direct TPMS and have for many years.

 

[heavyD]

Honda's "cars" (HR-V, Civic, Accord, CR-V) use indirect TPMS and have for many years. Their "trucks" (Odyssey, Pilot, Ridgeline, and Passport) use direct TPMS and have for many years.

Yeah that's what I said. It was around 2014 when Honda started using indirect for cars like the Civic.

 

[Big Dunc]

Why do we even need this? For 30 years I have checked my tyre pressures with a gauge once a week. Even if i was lazy and did it once a month, it would not be the end of the world. If you never check, you deserve the consequences of that. On our Model S, my wife recently had a puncture and she knew she had a problem and slowed down to pull over before the TPMS activated.
Previously we had a Cupra with the VW/Audi system. It was OK (we never had a puncture in that car), but one wheel had a slow puncture. I checked once a week and added a few PSI. The very next time it was driven, my wife would come in and say "I had to reset the TPMS again today". That means it was pointless, as after a few times she reset it without even checking the tyre pressures.
We recently bought a second set of wheels for the Model S for winter tyres. Genuine Tesla wheels with the TPMS sensors fitted. Only our Model S is an early one and the new wheels are from a a later car, so a different TPMS system. The early system is obsolete, so we now have to buy a complete new TPMS ECU and four new sensors (for the original wheels) and until we do that, every drive on the winter wheels we have an alert from the TPMS system. In the UK at least, it is not a legal requirement to have it (not for a 2014 car) but Tesla say there is no way of turning the system off.

 

[heavyD]

The average person doesn't check their tire pressures with a gauge weekly and these vehicles require the pressure to be at or above 40 psi as underinflated tires on these cars will wear fast and make for lower efficiency. That's why we need this.