Tires Size for CLA 200

[ray311208]

Hi Everyone,

 

Have anyone changed their tires to 235 or 245 on their standard 225/40/18. Any feedback?

 

Thanks in advance.

[jtang]

If your are thinking about it, pls don't do it. Upsizing the width but remaining at the 18" will screw up the speedo reading. The overall diameter will increase & you will get higher speedo reading then the real speed.

[zeenie]

If your are thinking about it, pls don't do it. Upsizing the width but remaining at the 18" will screw up the speedo reading. The overall diameter will increase & you will get higher speedo reading then the real speed.

 

Different definition of width. TS is asking about going up from 225 to 235 or 245. The width you are talking about is the "40" in 225/40/18, which would affect the speedo readings.

 

I think changing from 225 to 235 or 245 would need to change the rims as well? I'm no tyre expert and am curious about this too. 

[jtang]

Different definition of width. TS is asking about going up from 225 to 235 or 245. The width you are talking about is the "40" in 225/40/18, which would affect the speedo readings.

 

I think changing from 225 to 235 or 245 would need to change the rims as well? I'm no tyre expert and am curious about this too.

The width of the tyre DOES affect the overall diameter even when the profile remains the same (ie 40% in this discussion).

The formula for tyre diameter calculation is as follows:

 

Original tyre 225/40/18      (225x40%x2)+(18x25.41)=180+457.38=637.38mm

 

Proposed tyre 235/40/18   (235x40%x2)+(18x25.41)=188+457.38=645.38mm

 

Proposed tyre 245/40/18   (245x40%x2)+(18x25.41)=196+457.38=653.38mm

 

 

go figure....

[zeenie]

The width of the tyre DOES affect the overall diameter even when the profile remains the same (ie 40 in this discussion).

The formula for tyre diameter calculation is as follows:

 

Original tyre 225/40/18      (225x40%x2)+(18x25.41)=180+457.38=637.38mm

 

Proposed tyre 235/40/18   (235x40%x2)+(18x25.41)=188+457.38=645.38mm

 

Proposed tyre 245/40/18   (245x40%x2)+(18x25.41)=196+457.38=653.38mm

 

 

go figure....

 

Interesting. 

 

Didn't know the section width would play a part. I guess it's because the second number is an aspect ratio, and not a measurement. Interesting....

[LYH]

Interesting. 

 

Didn't know the section width would play a part. I guess it's because the second number is an aspect ratio, and not a measurement. Interesting....

 

That's right. The 2nd number is actually in percent. 40 means 40% of the preceding number. So moving from 225 to 235 or 245 will definitely have some effect