x-ray wrote:
I’m a little OCD about my cab (as anyone who knows me will testify to!) I like my tyre pressures to be spot on. On my Vito the TPMS reads in KPA not PSI. It works out at 310 in the front and 330 in the rear, they are so sensitive it takes me about 7 or 8 attempts to get it spot on !! It’s a good job I’ve got my own compressor. Incidentally, Shell garages are now charging £2 for air, I complained at my local forecourt and the manager blamed inflation!
Haha, didn't get the joke first time I read it
Not sure how much our Shell is now - last time I used them it was 50p, but Morrison's was only 20p, so guess which one I used? May be higher now - that was a few months ago, maybe last year.
I try not to get too fussed over my pressures - on my Passat estate the rears should vary between 32 and 44 psi depending on how loaded the car is, so obviously with a taxi you have to pick a happy medium, so I try not to get too obsessed.
I've got the *indirect* TPMS, so it just measures the revolutions of the wheel rather than measuring the pressure directly, so if the tyre loses air it will change how often it revolves and shows the warning light. Mine very occassionaly comes on for no apparent reason, and it's just a question of resetting it. It could be that as the tyres slowly wear and their circumference decreases then the system will detect that and think it's lost air. Or it's maybe just losing tiny amounts of air over time and it's nothing to worry about (although I'm not quite sure how much air has to be lost to show the warning light - I think it's actually a few pounds rather than maybe one or two pounds, or so).
It's a bit like the tyre wear causing the taxi meter to read slightly different because it changes how often the wheels turn