w209 tyre profiles

[ells_924]

hi all,

iv got some 18s on the car but would like to make the ride a little softer...

can i put a slightly higher profile tyres on the car. so 40/18 on the rear and 45/18 on the front??

 

[LostKiwi]

As long as there is enough clearance it should be ok. Put thecexisting wheel on full lock and check what clearance thete is and calculate from that how much will be left. In theory yoj need at least 5mm clearance. Its an MOT failure if it touches. Be aware it will affect your speedo readings.

 

[ells_924]

thanks for the reply kiwi,

what would happen if i put say 45s front and rear will it cause an issue with the traction control?

 

[LostKiwi]

thanks for the reply kiwi,

what would happen if i put say 45s front and rear will it cause an issue with the traction control?

The overall rolling circumference of front and rear axle must remain in the same proportion they are presently. If you increase the circumference at the rear and not the front the ABS, ESP, TPMS (if you have it) and cruise will all fail.

 

[ells_924]

thank you for that detailed reply,

i will look at 40 on the rear and 45 on the front

 

[LostKiwi]

Have a look at willtheyfit.com
It gives the relative sizes of tyre width/profile etc.

 

[JBell]

Wouldn't advise it, the 45 profile on the front is 3.41% and the 40 profile on the rear is 3.86% larger than the OEM tyres, max recommended change is + / - 2.5% to maintain gearing ratios and speedo accuracy

Try dropping your pressures by 2psi

 

[Wighty]

My 209 has tyre depths already of 40 and 45 with 17" wheels , so I'm not sure how you can have 18" wheels with the same tyre depth ?

 

[ells_924]

My 209 has tyre depths already of 40 and 45 with 17" wheels , so I'm not sure how you can have 18" wheels with the same tyre depth ?

I dont, i have the same as a normal setup on 18s but find the drive harsh and would like to soften it.

thanks for the advice all