Tyre Pressure Monitor type?

[robbee]

Hi guys,

Just a quickie to ask if anyone knows if in the UK we have the abs monitoring each wheel circumference rotation speed or if there is pressure sensor inside the wheel that transmits the current pressures?

I'm thinking of changing my wheels and would like to know if I need to install another set of sensors in the new wheels. And yes, I currently have the 296 and would like to swap them for the 293 styles.

Thanks for any help on this.

robbee

car is a September 2009 Z4 sDrive 35i

 

[Z4 Beemer]

Pretty sure its the abs that monitors things.

 

[All Pina]

Yep, rolling circumference monitoring. If there is any small difference with new rims/ rubber just do a reset to establish "normal" state. Assume you will stick to same width to wall ratios.

 

[robbee]

Yep, rolling circumference monitoring. If there is any small difference with new rims/ rubber just do a reset to establish "normal" state. Assume you will stick to same width to wall ratios.

Hi Alpina,

Sorry for a delayed response, but what do I need to look for to "ensure I keep the same width to wall ratio"? I have the 296 19" and want to change to 18" 293, as well as change the tyres to non-runflat tyres for a softer ride. I've never messed/changed wheels and dont know anything about sizing. I'm guessing your suggesting keeping the same aspect ratio for the suspension set-up to avoid un-even tyre ware?

Any help would be most welcome.

Thanks, and merry Christmas to all

robbee

 

[sars]

Yep, rolling circumference monitoring. If there is any small difference with new rims/ rubber just do a reset to establish "normal" state. Assume you will stick to same width to wall ratios.

Hi Alpina,

Sorry for a delayed response, but what do I need to look for to "ensure I keep the same width to wall ratio"? I have the 296 19" and want to change to 18" 293, as well as change the tyres to non-runflat tyres for a softer ride. I've never messed/changed wheels and dont know anything about sizing. I'm guessing your suggesting keeping the same aspect ratio for the suspension set-up to avoid un-even tyre ware?

Any help would be most welcome.

Thanks, and merry Christmas to all

robbee

You shouldn't need to do anything on the TPWS apart from reset it after changing them over, the system compares the rational speed of each wheel against the other three, a puncture results in a smaller wheel which has to rotate faster to complete the same distance.

Keeping the rolling diameter similar has to do with your speedo, so if you have 225/35/19 you need 225/40/18 for the fronts and 255/30/19 to 255/35/18 for the rear