tyre heights..

[Retro-gone.]

just how much actual difference in height is there between 185/70x13 and 185/60 x13 tyres when fitted to wheel? are we talking a full inch?

[johnboy]

Check out this great web site:

 

http://www.miata.net/garage/tirecalc.html

 

Type the two sizes in for a direct comparison.

[caprinerd]

10 mm tony

[over_head_cam]

The profile (eg 70,60, 55 etc) is a percentage of the overall width. So say you had a 205/50/13 you would be looking at an overall diameter of about 21 inches. A 185/70/13 would be Just over 23". the wider you go, the lower the profile needed to keep the rolling radius the same

[Copey]

70% of 185 is 129.5

 

and 60% of 185 is 111

 

so the difference is 18.5

[Retro-gone.]

18.5 what?

[over_head_cam]

slices of ham

[antz]

you saw the difference when comparing at against my wheels tony! I use 185/60s

[Messenjah]

18.5mm

 

 

the 185 measurementy is the width o the treaded section of the tyre in mm and the profile is a % of this as copey said ..

 

 

and thats 18.5mm difference in the diameter so 9.5mm each side

 

so basically a 10mm difference in the height of the sidewall

[Retro-gone.]

right ta

 

antz, i know i saw it but i didnt measure the difference.

[Fiesta Steve]

18.5mm

 

 

the 185 measurementy is the width o the treaded section of the tyre in mm and the profile is a % of this as copey said ..

 

 

and thats 18.5mm difference in the diameter so 9.5mm each side

 

so basically a 10mm difference in the height of the sidewall

 

The percentage is of the height of the sidewall, which is 18.5mm approx 3/4 inch, not 9.5mm

 

So the tyre will be 1.5" taller in total.

 

Don't forget a change in tyre size that much will alter the gearing noticeably.