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[TazioNYC]

Any ideas as to the best set-up that will fit on the stock 135i wheels? I've seen 225/40/18 front and 255/35/18 rear in a few posts. Would 230 tires fit in the front?

[TazioNYC]

Sorry, meant 235s in the front.

[mikeo]

The 235x40 could be made to fit, but they wouldn't be best for performance. Stick with 225x40 on the 18x7.5 OE wheels. JMO.

[d3syd]

So are we saying that stock tyres will fit on the OE rims? I thought that the OE rims are specially designed for run flats.

If stock tyres fit, I wonder whether the air pressure monitoring system will work?

[Rephlex]

Originally Posted by d3syd

So are we saying that stock tyres will fit on the OE rims? I thought that the OE rims are specially designed for run flats.

If stock tyres fit, I wonder whether the air pressure monitoring system will work?

Proper tyres work fine on the OE rims.

I run proper Continental tyres on Hartge aftermarket 19" rims and the aire pressure system works fine.:smile:

[atr_hugo]

The Bridgestone folks in Chicago said the sidewalls and beads of the tires, of course, are different compositions for runflats, but as Rephlex has said, they use regular rims (unlike the Michelin TRX tires from years ago).

[TazioNYC]

The Bridgestone RE-01R looks pretty good at that size...

[Advevo]

Best tire setup for this car is on stock rims

225/40/18 fronts 7.5j
245/35/18 rear. 8.5 j

With this setup you reduce understeer.

Don t go with wider rear tires it only gets worse. I have no shorter gearing and the rear 245 have stil grip enough.

Maybe the best setup would be 235 all round. But 235 on 7.5j rims are not nice. 8 j and 235 are perfect. But fronts are 7.5 j and rear rims don t fit on the front. They hit inside of the shocks.

When my fronts are gone i go for 225/40/18.

[mikeo]

Thanks, Advevo, for that real-life information. I still have hope that with aftermarket 18x8.5 wheels with proper offset (around et40, or small front spacers) that a square 245x35 tire setup will be possible. Only time, and little trial and error, will tell.

[dna550]

The last time I saw this discussed, I didn't see matching high performance summers tires available in the OEM sizes.

[I quickly checked the Tire Rack a few weeks ago.]

Has this changed?

One more question:

What is the procedure for de-activating the Tire Pressure Monitoring System when you move to non run-flats?

[mikeo]

The TPMS system on these cars includes devices and special valve stems that mount on the wheel and the electronics in the car. I have yet to hear of a way to disable the electronic system entirely, but removing the TPMS hardware from the OE wheel and installing them on different wheels works fine if they aren't damaged. You can also buy a new set of TPMS wheel hardware from TireRack, and others, for over $200 a set.

[TazioNYC]

If you bump the rears to 255, the choices widen:

click here for Tire Rack choices

[dna550]

BMW 330i: Run-flat Redux

http://blogs.edmunds.com/.ee95fbf

[TazioNYC]

Based on that, I wonder if I should take the run flats off right away...potholes and rough roads are only slightly less prevalent in NY than in Massachusetts.

[Joey_T]

Originally Posted by mikeo

The TPMS system on these cars includes devices and special valve stems that mount on the wheel and the electronics in the car. I have yet to hear of a way to disable the electronic system entirely, but removing the TPMS hardware from the OE wheel and installing them on different wheels works fine if they aren't damaged. You can also buy a new set of TPMS wheel hardware from TireRack, and others, for over $200 a set.

TPMS system does not include any special devices. It just senses differences in pressure using ABS sensors - which measure the rotation speed of the wheels and compares the measured speed to it's memory (set by driver) and signals if there is a difference. That's why the system needs to be reset after a tyre/pressure change - it needs to recalibrate it's memory.

And it will work the same for any kind of tyres.

[mikeo]

Originally Posted by Joey

TPMS system does not include any special devices. It just senses differences in pressure using ABS sensors - which measure the rotation speed of the wheels and compares the measured speed to it's memory (set by driver) and signals if there is a difference. That's why the system needs to be reset after a tyre/pressure change - it needs to recalibrate it's memory.

And it will work the same for any kind of tyres.

Joey, you're right if you are talking about the 'Indirect' system used on pre Mid-2007 cars. They changed to the 'Direct' system using wheel hardware after that. So our cars will have the new hardware TPMS system.

[ChrisK]

Mikeo is correct...I can confirm. I saw the special TPMS valve stems on the 135i at the Chicago Auto Show.

[MerlinMc]

Originally Posted by mikeo

Joey, you're right if you are talking about the 'Indirect' system used on pre Mid-2007 cars. They changed to the 'Direct' system using wheel hardware after that. So our cars will have the new hardware TPMS system.

Any implications with this new hardware and the use of a foam tire repair kit?

[mikeo]

Yeah, using fix-a-flat pretty much screws the TPMS on that wheel. New TPMS wheel unit is $40-$50.

[mateo]

I hear good things about Gen-2 Runflats. I don't think I will change them until they are more than ready.

[Joey_T]

Originally Posted by mikeo

Joey, you're right if you are talking about the 'Indirect' system used on pre Mid-2007 cars. They changed to the 'Direct' system using wheel hardware after that. So our cars will have the new hardware TPMS system.

Really? Did not know about that, my bad then.

[mikeo]

Joey, no my bad. Direct TPMS is a USDOT requirement--I have no idea if Slovenia requires the Direct system, I would hope not.