545smg

Without a tire pressure monitor - lets just say you're driving from one city to another (150mi).

You go over a nail in mile 1,

the mfg suggest 50 plus miles on rf - then what?

Your tire starts leaking, but with your confident rf's your crusing at 90 mph, and you lose your air, the car starts going out of control,

best case scenario - you ruin your tire, damage your wheel,

Then go into the back and go for a change of the spare. Right?

Why not just stick to the performance tire,



Scenario 2
You seem feel weirdness while you're losing air in mile 1,

Your so ill confident in your performance tires that you stop to check out whats up?,

you notice that you have a flat,

you change the tire,
-

conclusion:

new rf's $225

new wheels $600

a can of tire goo and performance tires,

priceless.

Rudy

I'm a little confused by your (disconnected) logic.

The key to using runflats is that you must have a tire pressure monitoring system so your first scenario is based on a false premiss...

Am I missing something?

EBMCS03

Huh? There is a run flat tire sensor... uses the ABS sensor and detects when the wheels are spinning at a different rate and then *blings* and warns you.

I've had 3 nails in 3 months in my MINI... they are equipped with run flats also. even with no air in the tire you can drive it w/out any problems... they so call recommend 50 miles ish... I think new run flat tires are up to 100miles of driving even when flat... EVEN if its extensive driving with a flat run flat tire it will not ruin your rim, you might not be able to re-use the tire anymore but you can drive on it it'll be ok. You'll be suprised how tough run flats are.

You'll never go out of control with run flats even if one tire completly loses air instantly...

545smg

What if you are just upgrading wheels - do they come with sensors?

Rudy

The sensors are rotational. They work with any wheel/tire combination. You simply have to initialize the system once you're sure all the pressures are correct.

The downside to a rotaional system (vs. discrete sensors) is that you can't see the exact pressures at any given time, you only get warned when the pressure of one tire drops significantly...

EBMCS03

Theres no sensor in the wheel so you wont have to worry. The system uses the ABS sensor to sense the rotation speed of each wheel compared to the other 3 and if one wheel is spinning at a different rate then it will tell you. From experience it will warn you with about ~5 lbs difference in air...

cobradav

It also does not tell you which tire is flat, so you need to keep a good tire guage in the car so u can check pressures. I have kept a good guage in my cars for almost all my driving years. Key to good tire life (and safe driving) is keeping those pressures where they should be.

Ricracing

I still think the RF's are not ready for the market yet.

Too hard and noicy.

I have not had an punture for 20 years (but now saying this I will tomorrow).

nicke60gre

Theres no sensor in the wheel so you wont have to worry. The system uses the ABS sensor to sense the rotation speed of each wheel compared to the other 3 and if one wheel is spinning at a different rate then it will tell you. From experience it will warn you with about ~5 lbs difference in air...
[/quote]

Get some infos now, from BMW TIS CD. (10 sheets)
If it is too much, ask me to cut some pages.

Ågent99

I think BMW should include a tire pressure gauge in the car if they continue to equip them with runflat tires.

I got one while on vacation several weeks back...pulled into a gas station...bought a cheapie gauge...everything was fine.

According to the manual, "spirited" driving can cause the montor to go off! Gee, I never do that.... <_<

However, I've only had a false positive once thus far....