Hi everyone,

I am new to this forum, and I have a question that I would like to get answers from fellow Mini drivers. I have a 05 MCS and I would like to change the tires and wheels, but I was wondering about the tire pressure monitoring valve (transmitter) that's currently on my factory runflats. Do I need to have them swapped out to the new set of wheels and tires? Or do I lose this feature (tire pressure monitoring) when I switch to different wheels and tires?

Thanks in advance,

 

The MINI does not come with the transmitter built into the valve stem. The sytstem works off the ABS sensor. So that means you can use any time of wheels/tires of your choice.

 

The tire pressure monitoring system in the MINI is a bit of a misnomer. There is no actual pressure sensor in the tires, instead the system relies on the circumferential change of a low/flat tire and subsequent rise in wheel rpm relative to the remaining three wheels to alert the driver. Think of it more like a 'low pressure detector' rather than an absolute measurment of the pressure in each tire. The system makes use of the ABS sensors in each wheel to 'count' the revolutions as you travel. A low tire is effectively made smaller in diameter because of the flattened contact patch. A smaller tire turns more often than a larger one traveling the same distance. The counts obtained from each wheel as they roll down the road are compared to one another, and if one happens to be significantly higher than the rest, the system assumes it is due to low tire pressure and lights up the warning on the dash.

Here is the main problem with a system of this nature -- if all of the tires are equally low in pressure, there will be no difference noted among them and therefore, no warning will be given.

To sum it up, the MINI uses ordinary valve stems, with no pressure monitoring sensor. You can mix and match tires and wheels and ordinary valve stems and still retain the the flat tire monitoring system.

 

No worries, there are no monitoring things in valves or wheels or anything.

The tire pressure system works by measuring the differences in relative speed of the wheels, via the ABS sensors, etc....

 

So even if i replace the run flats with normal tires, the system will still work?

 

Ah... That makes sense. Thank you guys so mauch for clarifying this issue for me. All I need to do now is to decide on which wheel and tire I am going to buy.Thanks Again,

 

I was wondering about that too, the salesman had told me this but I thought it was full of BS, especially after he told me I could NOT put any other tires on my rims, they were specially made for run-flats only, after he said that, I thought to myself, that guy is full of sh**.

Now my question is I have the low tire warning light on and I thought it was due to the fact I had replaced the wheel and tires, I checked the tire pressure and they are all at 38 psi, I ignored the waring since I thought it was the missing sensors, now if there isn't any sensors and my tire pressure is fine, why do I have the warning???

 

I know this is going to sound like an IT helpdesk, but did you try resetting the sensors?

 

There is a reset button for the low tire pressure warning system near the parking brake and gear shift. I believe the procedure is to turn the key on to the first stop, press and hold the button for a few seconds, and then continue to start and drive the car. The system should recognize the tire rotation and reset itself in a few minutes or less.

 

Thanks guys, I can certainly do that, but my question now is, why did it set the warning in the first place, I went from 38 psi stock wheels to 38 psi aftermarket, so what is it that sets the warning, did any of you had this warning after swapping wheels?