Tyre Size

[type81]

my audi 80 has the 6x14 45et ronals with 185 60 14 tyres, if i were to go 1 up to the 7x15 42et then i can use 195 50 15 tyres, is this correct??

[Micky]

you should use 195/55/15 you can use 50s for a lower profile but you speedo will be out

[type81]

interesting, i always thought that an inch bigger in wheel size and you decrease the profile by 10

[Micky]

dont forget you are also going from 185 to 195

[type81]

Originally Posted by Micky

dont forget you are also going from 185 to 195

But thats the witdh, that wudnt really affect the rolling radius profile speedo thingy, wud it?

[Micky]

the 50 or 55 is a percentage of the tread
so a 135 / 50 is not the same as a 155 /50 the 50 is not the same on all tyres its only a percentage so all are differant diameters

just get a spare tyre take it to a fitting place and put them side by side and look at the hight differance .

[type81]

thanks micky

[Martc]

You have two options

195/55/15's

or

205/50/15's

I would go for 195/55/15's which is what is going on my 7jx15 ET42 Ronals

[type81]

theres no power steering so 195' is what il go for, yep them ronals are nice

[pimpdriver]

Originally Posted by Micky

you should use 195/55/15 you can use 50s for a lower profile but you speedo will be out

Stop: wrong.

185/60R14 = 578mm diameter

195/50R15 = 576mm diameter (-0.35% difference)

195/55R15 = 596mm diameter (+3.11% difference)

http://www.etyres.co.uk/tyre-size-calculator.htm

Don't get 55 profile, your speedo will be out, 50 profile is correct........