Help with wheel configuration settings for new 20inch wheels

[midnightblues]

Hi All -

put a set of Tire Rack purchased winter wheels/tires (with new TPMS) on the car, which then asked me to select a new wheel configuration setting. Only options in the menu are the OEM 19 or 21inch wheels and various configurations. The wheels I purchased are 20inch - any advice on what to input here, or will it make no difference?

(TPMS values also seem to be weird, will try a TPMS sensor reset once I’ve figured this out)

Any advice much appreciated!

 

[kev1n]

prob go with 21 setting so that the warning psi is lower(to come on) and your speed reading will be higher than actual. 19's will be vice versa. either way should be fine though

 

[midnightblues]

prob go with 21 setting so that the warning psi is lower(to come on) and your speed reading will be higher than actual. 19's will be vice versa. either way should be fine though

thanks!

 

[Saleen09]

I have a set of 20" Vossens and have it set to 21" for the TPMS reasons above. Also, the wheel size between 19" and 21" changes range calculations as well.

 

[quickstrike12]

Surely the tire size doesn’t effect speedometer.......
This setting is for range calculations is it not?
I would have thought the speed is taken at some other rotation point like the gearbox maybe so it’s fixed......ICE cars typically measure at the transmission to avoid this problem.

it’s a good question and now it has me wondering also.....

 

[brkaus]

I think it changes range and the picture of the car displayed on the screen & app.

the outside diameter should be the same between the various combinations. Or at least very close. Treadwear changes the diameter too.

 

[aznkukuboi]

I have a set of 20" Vossens and have it set to 21" for the TPMS reasons above. Also, the wheel size between 19" and 21" changes range calculations as well.

I thought this was supposed to be true, but when you change from 19's to 21's, my estimated range doesn't change at all. So I'm not sure if it's a bug or I'm just expecting the range to go down.

 

[Saleen09]

I thought this was supposed to be true, but when you change from 19's to 21's, my estimated range doesn't change at all. So I'm not sure if it's a bug or I'm just expecting the range to go down.

It does affect the dynamic calculations and ideal range.

 

[Naekuh]

prob go with 21 setting so that the warning psi is lower(to come on) and your speed reading will be higher than actual. 19's will be vice versa. either way should be fine though

FYI 21inch has a tire pressure of 43 as well and that warning lights screams when u go below 39, i dont know what it is for 19 stock tho, but i would assume the low pressure warning was higher on 21's as even the slightest bit of low air means greater risk of you cracking your rim in a pothole.