I understand that the run flat sensor is really a part of the ABS system that senses a differece in the diameter of the tire once the system is set. If you change the size of your wheels and tires either larger or smaller will the system still work?

 

I would too like to know the answer I upgrade to 17" wheels and when I got a flat the other day the run flat light did not come on !

 

As I understand the monitor works by measuring the difference in speed of each wheel. I assume a flat tire will spin slower.

 

Exactly. It measures the difference in wheel speeds. The worst thing that might happen is that you would have to reset your tire pressure monitoring system. With non-runflats, the monitoring system will do the same thing as if you had runflats.

 

Nope, a flat tire spins faster. Without air in it, the diameter is smaller. Smaller diameter wheel spins faster for a given speed.

 

I stand corrected. But thats how it works. It measures how the tire spins at a different speed then the rest of the tires.

 

So if all 4 tires are flat at the same time, the sensor would not detect a problem right?

So I am looking to get some new wheels and tires to replace the dunlop runflats and s-lites. I may just stick with same s-lites and some new regular non-runflats.

I can put non-runflats on the s-lites right? There is no difference for the wheels of runflats and non-runflats?

 

I dunno 'bout you guys, but I don't need my car to tell me when I have a flat.

 

Right! Or more likely, if you neglect to check the air pressure and all 4 tires lose air at about the same rate, the sensor would not warn you. You've been listening to the voice of experience !

You might if you were running runflats!

 

Isn't the premise of this thread that the runflats are removed???

 

Oooops so it is! My bad!

 

im running 205/50/16's. they work fine.

 

205/40/17 and the flat tire sensor works great. It detected a 5PSI loss in one of my tires when I ran over a screw a month or so ago.

 

Also, the flat tire sensor will pick up a smaller pressure loss in a non-runflat tire
than in a runflat tire, since the sidewall sags more with a non-runflat for a
given pressure drop.

 

Yes, you can put non-runflats on S-Lites - I did. I swapped my runflats out at 10,000 miles for BF Goodrich g-force Sports and the difference was night and day. The Sports are quieter, better riding and better handling in wet and dry. Unless the technology improves considerably I will never use runflats again.

/gary

 

I am about to do the same. The 3 possible choices are:

BP Goodrich G-Force Sport for $96/tire installed
or $384 total.
Treadwear 340, Traction AA, Temp A

BF Goodrich G-Force KDW for $131/tire installed
or $524 total.
Treadwear 300, Traction AA, Temp A

Michelin Pilot Exalto 2 for $162/tire installed
or $648 - $50 mail in rebate to Michelin = $598 total.
Treadwear is 240, Traction A, Temp A

They all look like they have fairly good reviews and test results on Tirerack.com. I will be getting these from the local Costco since you cant beat the service and free balancing/rotation and even flat repairs (assuming I can get the tire there without a spare )

Does anyone have any opinions on any of these? I am not sure if the Treadwear, Traction, or Temperature have any thing do to with how well a tire performs or lasts. Is this a rating from manufacturer or from outside unbiased source?

 

I guess the other option is to get some new lighter wheels and tires from TireRack. It would not be too much more $ if I went with 16 in wheels and probably a smoother ride too.

 

It's a flat tire alert, not just a runflat alert. Works with any type tire you have on your wheels. I check my tire pressure once a month and re-calibrate the system each time regardless of what the pressures were.

...Les

p.s. Sorry if I'm redundant.

 

I have the G-force sports and I love them!

 

Thanks for the info. Looks like you dont have them on factory wheels? 17 in?

 

Indeed if all 4 tires are low or flat, the system would most likely not pick up on it. There is a note in the owner's manual to this effect. Since the system relies on diameteric differential to work it's magic, if all the tires are equally low you wont get a warning. The warning system is not a replacement for regular air pressure checks.