Forgive my ignorance on this, but how do I know if my Run Flats have a puncture? And what does that little button do under the E-brake (something to do with resetting tire sensor?)?

Having no spare kinda freaks me out. Thanks for the help.

 

If the runflats won't hold air pressure, you have a flat. The runflat tires still use air; they just have the ability (through much stiffer sidewall) to run for extended distance with no air in them. The button under the E-brake is part of the flat tire monitoring system. It is used to reset the flat tire monitoring system.

 

Yes I understand all that. I was wondering how in the heck I'm alerted if I have a puncture? Will I be at all? Or will I figure it out 50 miles later when the tire is flat?

And what is the flat tire monitoring system? =O

 

it looks at the speed of each wheel via the ABS wheel speed sensors. If one of the wheels speed changes relative to the others, it's makes a low air call. It's a bit smarter than that to take into account turns and the like, but that's about it. So as the tire looses pressure, it settles a bit and the light goes on. I haven't tested it for it's threshold, but I think if you drop 5 psi or so it can go off. The button tells the system to re-learn what's good (for instance if a couple of the tires are new, and they have slightly different diameters, or if you run different tire pressures front to back, like lots of the track rats do), as all equal may not be right.

Matt

 

You will have a light that will illuminate and that lets you know either you have a flat or your pressure is low.

 

if you bought you car used and have no owners manual, you can download one from Mini USA. You may have to join the owners lounge (need the VIN for access)...

If you do have the owners manual, read it!

Matt

 

I think he would much rather post on NAM. Tha way he gets more information than is in the Owners Manual....

 

Made me laugh!

Matt

 

Yes I have a manual... but as most of you know it's a little lacking in info (to say the least). I do like the tongue in cheek way it's written though.

So basically, when I have a tire losing pressure a light comes on. Does it go off once I get the pressure back up to normal? Or do I push the button to "reset" it. Thanks again for the help =P

 

it might go off, don't really know! I just check my tires when it goes off to make sure they aren't too low. Reset the system, and add air at the next chance.

Matt

 

I know from experience (twice) that a gong will sound and an indicator light will flash in the center speedometer. You can visually see which tire(s) is flat, but you have to look carefully. If the trie is still sound, you will not be able to tell which is flat by driving the car.

My first flat occurred at speed (60 - 70 MPH). I would not have known there was a problem if the warning hadn't sounded. Both times I was lucky as the puncture was in the tread and the tire could be repaired.

Please be advised that the alarm will trip if the pressure in 1 tire changes significantly due to temperature change or by adjustment, even if there is no puncture. The alarm will not trip if all four tires drop equally in pressure due to a significant temperature change or you are unlucky enough to get four flats at the same time.

 

The light that comes on looks like a butt. My MA even called it the buttcrack light when he was telling me about it

 

This is actually a valid question. Most of us carry tire pressure guages in the trunk. that way, when the idiot light comes on, we can check the pressure at all four corners and determine if it's a false alarm, or whether we need to call Alex at TireRack.

 

I bet that info isn't in the owners manual.

 

if there's no leak you won't know until you visually inspect
the tire if you have a nail in it or not. but that's the same
way for normal non-runflat tires.

 

Hmm...

What did the manual say? I wonder why they would have a "reset" button

Yup, hit the button.

 

Just don't 'hit' it too hard! If it's like the emblem on the steering wheel, it will probably break.