I was wondering if anyone's running 205-40x17's on a MCS. I was considering it and did the math. My speedo will be off by about 3.4%, so 70 mph will really be 67.6 mph. Anything concerning the ABS calibration and other 'unforseen' things I should be worried about? Thanks everyone..... :smile:

 

nope, you can do this, as long as you know your speedo will be off AND you run this size on all four corners (that way the ASC, ABS, and tire-monitor won't be screwed up)

Why do you want to deviate from stock diameter, anyway?

Cheers,
Ryan

 

I'm running 205-40-17 Kumho mx's on 17 x 7.5 Kosei K1 wheels. Your about right about the speedo error. These replaced s-lites with Pirellis. The Kumhos are about 1/2" wider and a full 1" smaller in diameter so the car is 1/2" lower. So far I'm happy with this combo. They are a full 14 pounds each lighter than The s-lite/Pirelli originals! I'm going to run an open track @ Buttonwillow this weekend so I'll have a better feel for how well the Kumho's perform next week.

 

Just keep onj the high side of your inflation pressures to maintain load bearing capacity.

Dan

>>I'm running 205-40-17 Kumho mx's on 17 x 7.5 Kosei K1 wheels. Your about right about the speedo error. These replaced s-lites with Pirellis. The Kumhos are about 1/2" wider and a full 1" smaller in diameter so the car is 1/2" lower. So far I'm happy with this combo. They are a full 14 pounds each lighter than The s-lite/Pirelli originals! I'm going to run an open track @ Buttonwillow this weekend so I'll have a better feel for how well the Kumho's perform next week.

 

Thanks Dan. I'll start @ 36 psi per your recommendation. I have a probe type pyrometer so I'll check temps and pressures after each run, although the forcast is for rain all weekend so it will be hard to get much temp in the tires. That being so, would you go out @ a higher pressure? I'm curious about the recommendation for 36 psi. The specs on your web site for the mx's shows exactly the same load capacity (1102#) as the Pirelli Eufori's and the factory recommends 33 psi for them. What's the difference? Rain on track days and the desire to change tires @ home and drive to the track instead of lugging all that stuff with me is why I bought a street tire instead of an "r" compound dot approved tire. Your test results showed the mx as pretty good in the rain!

 

>>nope, you can do this, as long as you know your speedo will be off AND you run this size on all four corners (that way the ASC, ABS, and tire-monitor won't be screwed up)
>>
>>Why do you want to deviate from stock diameter, anyway?
>>
>>Cheers,
>>Ryan

Just a little more selection in tires at this size. The 205-45x17's are a little odd. My guess though that with the popularity of the Mini you'll start seeing more in this size. Thanks for your help......