[DR-JEKL]

Originally Posted by pavo335

the tpms in Australia is a sensor on the wheel bearing not a sensor in the wheel like the states. I suspect any "mobility" kit is designed for an emergency not prolonged use and would require a through clean.

Can you explain what you mean by the tpms isnt mounted in the wheel???

I believe the valve stem is a tpms and is the 'transmitter'????

[eriktufa]

It is only a sensor that reads wheels rotation speed and calculates your tyre pressure.

It is NOT actually a proper TPMS. VW use similar system so you won't actually find TPMS sensors inside your wheels.

I hope I'm right.

[DR-JEKL]

Originally Posted by eriktufa

It is only a sensor that reads wheels rotation speed and calculates your tyre pressure.

It is NOT actually a proper TPMS. VW use similar system so you won't actually find TPMS sensors inside your wheels.

I hope I'm right.

Hmm I don't think so explain how this would monitor tyre pressure??? tyre/wheel speed has no relation to tyre pressure. My rims have the valve stems that the beru tpms have, so yes we do have tpms in the wheel, I believe the tpms has a transmitter in the valve stem (mounted in the wheel) and the receiver is inside the wheel well (abs sensor?)

[eriktufa]

http://www.my-gti.com/321/volkswagen...ng-system-tpms

Good way to explain it. We have indirect TPMS.

[pavo335]

definately no in wheel sensor, it is a rotational sensor on the wheel bearing

[Max555]

Originally Posted by DR-JEKL

Hmm I don't think so explain how this would monitor tyre pressure??? tyre/wheel speed has no relation to tyre pressure. My rims have the valve stems that the beru tpms have, so yes we do have tpms in the wheel, I believe the tpms has a transmitter in the valve stem (mounted in the wheel) and the receiver is inside the wheel well (abs sensor?)

Spoke to the dealer once who explained it. When a wheel loses tyre pressure it has a slower rotation than the wheel on the other side, and this is the principle that it works on. This also explains why many members have reported running completely flat tyres without the system detecting the pressure drop, especially with the low profile tyres most run.

[moebius99]

Originally Posted by pavo335

the tpms in Australia is a sensor on the wheel bearing not a sensor in the wheel like the states. I suspect any "mobility" kit is designed for an emergency not prolonged use and would require a through clean.

Moved to Non-RFT and bought the mobility kit - never had to use it though.

[DR-JEKL]

Originally Posted by Max555

This also explains why many members have reported running completely flat tyres without the system detecting the pressure drop, especially with the low profile tyres most run.

Yes this system seems absurd, how much deformation will there be in a 30 series RFT, sfa and of course the system wouldn't pick it up. Once again I can't believe how shortsighted bmw have been, and why they wouldnt opt for a direct system TPMS!!!

So can one in Australia fit a us bmw beru type system to ones Australian delivered bmw?

[pavo335]

Don't know about a retro fit but I can say for a non rft the system works ok.

I normally run 40psi in the fronts cold and I had a slow leak an the warning popped up when the pressure dropped to 30.

[DR-JEKL]

Originally Posted by pavo335

Don't know about a retro fit but I can say for a non rft the system works ok.

I normally run 40psi in the fronts cold and I had a slow leak an the warning popped up when the pressure dropped to 30.

is that with 35/30 series tyres?

[Scootah]

Dr J

I have non rft on my car and aftermarket rims , and system works fine

30/35 series tyres

Like Pavo mentioned , picks up anything above @ 5 psi pressure drop

As I understand works on wheel rotation not tyre pressure sensors

[pavo335]

Originally Posted by DR-JEKL

is that with 35/30 series tyres?

Yep. 235/35 and 275/30

[Max555]

Originally Posted by pavo335

Don't know about a retro fit but I can say for a non rft the system works ok.

I normally run 40psi in the fronts cold and I had a slow leak an the warning popped up when the pressure dropped to 30.

Looks like another good reason to move away from RFT's

[_ink]

It makes sense to me. Wheel rotation speed is definitely affected by tyre pressure.

And for the people that go aftermarket rims, it's a blessing in disguise to still retain this functionality.

[DR-JEKL]

Can someone confirm what type of valve stem they have on their 335's?

I have the original rims on my car, and the valve stem is exactly the same as the tpms beru valves below (silver also!):



My valve:



So it would appear that perhaps earlier model 335's came with a direct tpms and as pavo has stated some work off tyre rotation speed (later models?)

The reason I ask is that I'm ready to mount a new set of tyres and rims and don't wish to waste $ by adding my new tpms valves if I don't need them or vice versa have the tyres mounted and realise I need them!

[pavo335]

sorry cant help, my intuition would say that all aus delivered cars have the same tpms system BUT anything is possible. i wonder if there is a way to tell from the vin deconder thing....

[Zen]

not sure about what valve stem i have, but afaik my tpms is based on tyre rotation.. and mine is a e92 08 model.

[_ink]

Originally Posted by Zen

not sure about what valve stem i have, but afaik my tpms is based on tyre rotation.. and mine is a e92 08 model.

+1

Mine look nothing like what DRJEKL posted up.

[DR-JEKL]

Originally Posted by _ink

+1

Mine look nothing like what DRJEKL posted up.

Hmm probably confirms that perhaps the earlier models have direct tpms valves fitted... As I'm sure we would all agree the valve stems on my oem rims are a deadset match for the beru tpms valves.

I believe bmw changed their diffs (bolted ring gear to a welded ring gear) as that it cut costs, perhaps this was also a decision on later models to cut costs by implementing an indirect TPMS also?

How did the LCI tails go Ian?

[eriktufa]

Pretty sure No Oz BMW comes with TPMS as there will be an option in your Idrive to set it and monitor it.