q

 

the Run-Flat pressure sensor is a relative comparison of the diameters of the four tires. Therefore, you shouldn't have a problem

 

The tire pressure sensor doesn't measure tire diameter. At least not directly.

The car has an ABS wheel speed sensor at each wheel. This is how it knows if a wheel is locking up so it can activate the ABS system.

MINI in their infinite cheapness...er, resourcefulness :smile: decided that they could make a ghetto tire pressure monitoring system out of this :smile:

It uses the ABS wheel speed sensors to measure the relative rotational speeds of each wheels. As long as each wheel has roughly the same rotational speed, it assumes all is well. If a tire goes flat, the wheel diameter decreases and the rotational speed increases relative to the other wheels, and this triggers the warning light.

So if you put 18s all around, you will be fine unless one goes flat :smile:

 

>>MINI in their infinite cheapness...er, resourcefulness :smile: decided that they could make a ghetto tire pressure monitoring system out of this :smile:


I woudn't call this cheapness or ghetto... granted, it's the cheaper of the two types of flat tire monitoring system, but the more expensive one requires sensors in/on the rims. It's just a matter of Passive vs Active monitoring.

Rocketboy_X
(PS. Scary thing is, is that the US Gov't is requiring all cars made after, oh 2005 I think, (maybe 2008) to have flat tire monitors. Thanks guys, I'll still be blinded by SUV's with ultra-bright headlights :evil: )

 

>>I woudn't call this cheapness or ghetto... granted, it's the cheaper of the two types of flat tire monitoring system, but the more expensive one requires sensors in/on the rims. It's just a matter of Passive vs Active monitoring.
>>

Yeah, I know. It was tongue-in-cheek. I think it's a clever way of providing the tire pressure monitoring capability without the added expense of pressure monitors. Good solution to keep costs down.

It won't work as accurately as a proper system but it works well enough.

 

Makes it much easier to change out the wheels however. And the flat sensors do work as I had the misfortune to discover.

 

Just reset the sensor when you put on the new wheels and it should work fine. Please post pics of your MINI once you get the 18's on it!