I'v orderd my new wheels and the 17s that are on it have 205/50/17 so i think 225/45/18 will fit. I need 45 for safety as Irish roads have pot hole that pop out of no where, so do ya no any1 wit 18s that have a 45 profile?

Thanks. Kel

Won't this make the wheel diameter to big. :confused:

I would have thought going bigger than 40 profile with 18s would cause all kinds of problems... :confused: I can't be ar5ed to plumb the sizes into the tyre calculator... I'll let someone with more time do that... (denis? :P)

3.6% increase in circumference. Is that too much, Des?

I've got 225/40/18....the 45 profile will give quite a bit of error on the speedo.

If you're concerned about potholes stick with the 17'' alloys.....the 40 series tyres for 18'' make for a stiffer ride.

LCR runs a 225/40 R18 tyre

LC runs 225/45 R17

Octy vRS runs 205/50 R17 tyre

All of these have the same rolling diameter.

225/45 R18, if you can find them, are too big.

More than 3% is not good for the other bits, like brakes etc.

However if you must and I know the Irish roads, or at least the last cars belly does (tip never run low road settings in Ireland) I forgot to raise it okay..

Anyway: Speedo reading stuff.

O--> Target Tyres

30 31.08

40 41.44

50 51.8

60 62.16

70 72.52

215 45 18 might work, only 2.18 % difference, but that requires your Rim to be 7.0 to 8.0in, which I suspect is still okay...

However 205 45 R18 are only 0.77% out. Or

Speedometer Results KPH[/b]
Original           Target                               
50           50.38                               
60           60.46                               
80           80.62                               
90           90.69                              
100           100.77                              
110           110.85                              
120           120.92                              
130           131  

Heres a nice easy calculator

http://www.tyresave.co.uk/tyresize.html

And as has been said over 3% change may put extra strain on brakes Etc

Thanks for they info lads, i'v put they order in for 40 profile. Might make the wheels look to big runing wit the 45's. Need the car to look rite!

Kei,

Could you tell me what width of 18 you've got i.e 8.5inch ?

I'm in interested as I'm looking for some hoops myself at the moment.

I've noticed that some "wheel deals" offer 235/40/18 as well as 225/40/18.

Pete

Hi stathap, the wheel i'm going for is a FOX RS5 which comes in a 8" by 18" I don't no if the 235 tyre will fit or not but i do no it will slow u down more, the 225 should hold the raod fairly well.