can i ask if anyone on here is running 225/40/18 on a classic?

i know the general corect sizes are usually the following...

205/50/16 radius = 305.6mm
205/45/17 radius = 308.2mm
215/40/17 < currently mine radius = 301.9mm
215/35/18 radius = 303.8mm

now the 225/40/18 has a raduis of 318.6mm


besides the slight speed reading issues, would it scrape either the arches on full lock or my mudflaps?

any pics advice welcome, thanks.

 

I'm running 225/35/18 on an et 53 without issues. I did think that the 40 profile had issues with the spring platform as it's 26mm bigger diameter than a standard tyre. It's 22mm more than mine and I don't think there's that much space.
Thanks,
Paul.

 

well i got my figures from the follwing site... Tire size calculator

as i was trying to work out how much bigger they would be over my current ones. so the difference between 301.9mm and 318.6mm worked out to be under 17mm raduis and 5 mm each side width wise. my main concern was rubbing of the arches and suspension shocks. for the record i have gas adjustable shocks (agx kyb - stiffest setting) and eiback springs. the rear is a little lower, the front a tiny bit. rarely have more than two in the car and never have rubbing issues with current tyres.

 

I've got the same suspension set up as you and 225/35 on the correct ET are not an issue. The trouble comes, on the 40s, from the small gap between tyre and spring platform when the tyre moves, obviously it doesn't move far as the strut, wheel and tyre are fixed together but the tyre does flex and rub on the strut or so I've been told.
I use this site for tyre sizes: TYRESAVE: Tyre Size Calculator
Thanks,
Paul.

 

I'm running 225/40/18's on my STi v3 - front clearance is fine, rear strut spring caps need a little 'fettling'.....doesn't need much, I managed to find the clearance using a 4lb lump hammer and an old 12" 1/2 drive extemsion as a dolly. When fitted originally I was running Prodrive/Eibachs. Now running KYB's and Eibachs.

Here's how they look.

 

225 35 18 is what im running

 

I had 18"s on my RA but changed to 17's as they provided a better drive I found 18's way to hard but that was just me

 

Had 18s on mine clearance was fine but like peeps have said to hard 17s much better and also u get better 1/4 mile times

 

Anyone know what affect (if any) running 18" on a dccd equipped car has?

 

i run 215/35/18 on mine fitting eibachs an kyb in the next couple of weeks

 

it doesnt matter now anyways. id seen a bargain on ebay and before i knew it, gone, snapped up by someone else