Thread: 135 spare tyre
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      07-07-2016, 05:05 PM   #25
Dackelone
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Quote:
Originally Posted by champignon View Post
I believe that this may be incorrect for the US cars, using the TPMS sensors in the wheels.

I know from my ownership of Subarus, that if people put winter tires on without sensors in them, that they would get the warning light after driving a few miles. Then, when they parked in their garages (containing the removed summer tires with the sensors still in them) the system would reset and they could again drive a few miles, after which the system would again show the warning light.

This is what my US 135i(2010 model year) TPMS low tire light looks like. Note this pic wasn't from this trip.
Name:  TPMS low tire  4.jpg
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I'd imagine that the BMW system for cars having the sensors in the wheels would act somewhat similarly, and if not exactly like that, would still sense a non spinning wheel in the trunk containing a sensor. If the tire was not inflated, then the warning light would go off, just as it would if the tire was not there at all and had been replaced with a non-sensor containing spare of some sort.
Noop.

A few years back, when I had my mini donut spare tire with me in my trunk... I was at Nürburgring for the AvD-Oldtimer-Grand-Prix, I was staying up in Leverkusen and commuting to the 'Ring that weekend. On race day morning when I went to drive to the track(7am) I saw my TPMS light on and pointing to a flat tire. I installed my mini donut and drove to the 'Ring. It began to rain and that's when I discovered the joys of driving with one 255 tire on my right rear and one 125 section tire on my left rear. The car would wag it's tail any time I even THOUGHT of accelerating gently. It was damn scary.

Once I got to the 'Ring... I called a buddy of mine who lives near the 'Ring and he loaned me use of one of his 18 winter tires(without a TPMS!).

My point is... even with the mini donut on my car, and my flat tire in the trunk... my TPMS light was on! The system knows IF a wheel(w/a TPMS sensor) is turning or not.

Btw... I was sooo happy by buddy lent me his winter wheel. I was NOT looking forward to driving some 550 kms at 80 kph on the Autobahn with my mini spare. And besides it probably would not have made the entire 550 km trip back home without some sort of melt down or blow out. It was then on that trip back home... I decided to ditch the mini spare and buy a full size spare! On that trip back to my house... I was able to zip back at a safe 240 kph(W rated winter tire!) with that winter wheel! Life in the fast lane.

I drove home with my mini spare in the back seat and my flat 255 wheel in the trunk.

Dackel
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