Quick question... My boss was driving a rental car...It is an 07 Impala....it has a warning light that came on for low tire pressure....it said pressure was 24 lbs in the left front wheel....It did have 24 in it...Aired up to 30, turned key on...it showed 30 lbs.... Does anyone know how this works?? How does it read this pressure?? Willy
I would guess they have tire pressure checkers some where on the car, and like it'll check it once the car is started or check it after a certain mileage or something.
i would guess the tempurature cause in the winter on my 06 monte carlo the sensor gets all screwed up
Early TPMS used the wheel speed sensors in the ABS system to find a low tire. Not quite as accurate, but they did work. A low tire is "smaller", so it has to roll more to cover the same ground as a fully inflated tire. The speed sensor would catch the "faster" rolling wheel, and flag that corner as being low. The new generation, which will be government mandated in 2008, I believe use a different system. They basically send a signal to a TPMS control module that translates the signal to pressure. It monitors it at all times at differing intervals. Key off, less frequently, Key on engine running, far more frequently. When your tires are rotated, and you have that system on there, don't be surprised if it costs a bit more. Some will auto-initialize, other have to be initialized with special tooling. So, when the price of a rotate jumps, don't blame the poor ol tech or shop that's doing the job. Blame the morons that don't know how to check the air in their Explorer tires that blame everyone but themselves for their accident.
Some one how thinks like me. They blamed everyone else but the owners of these vehicles had to be idiots. Ford put door stickers on the doors that recommended 26 psi in the tires, but any one smarter than a monkey should have known better. My wifes car has 32 psi on the door sticker. We live in Texas and she drives to Arizona on a regular basis. The tires have a max pressure rating of 44 psi. I keep 40 psi in them (if I'm wrong please tell me). The car drives normal and there is no unusual tire wear patterns. Had to add my 25-cents worth
You got it Ranger. When one of those came in for an alignment, they got 32 in their tires. If the customer didn't like the ride, it was up to them to change it. But, it left with what I felt was the minimum I felt they should carry. Same with any service I did. They got 32. As far as your car, I am a firm believer of looking at the tire, and take what the door jamb says with a grain of salt. Run as much air as you can without adverse tire wear, and it is a win/win. Gas mileage, everything. Here in Denver, I will lower my tires down to 32/35 because of the snow and resulting sand. Strictly for traction reasons.
