oakcreekeric

Hello

I'm in the process of upgrading into 18" rims from the standard 17" that came with the car (03 SL500) - in doing so, I will take this time to install new TPMS sensors -

My question for those who have changed wheel/rim diameter - what will I do about the TPMS readings - I'm not 100% sure what the pressure I'll need to run, but I'm guessing it would be different than the stock 17" ??? or do I just use the pressure recommendations inside the door/fuel cap ?

Also, will the new tires effect my speedometer ?

Thanks

brucewane

Use the pressure recommendations inside the door/fuel cap. The recommended pressure does not change with tire size. Technically speaking, the volume of air needed to achieve a specific pressure will change with tire size, but we don't measure (or care) about air volume.

As long as your new tires are about the same outer diameter as your old ones, your speedometer will be OK. Typically, when you go to a larger diameter wheel, you also go to a tire size with a shorter sidewall so the tire outer diameter remains about the same.

For more information on R230 tire sizes, read this thread - https://mbworld.org/forums/sl-class-...eel-setup.html