imprezered

Hope someone can help.

I have a set of 18's fitted to my classic with 215/35/18 tyres. The ride is really harsh and any pot holes feel very bad. It also tends to under steer when flying around Donnington Park!

I've decided to change them for 17's but I'm getting conflicting information on the tyre size. I'm going for 17" KEI Force 10 but have been told that they should be fitted with 215/40/17 by one supplier and 215/45/17 by another.

Can someone tell me which size is the correct one please.

Thanks
Mick

mattjbvfr

215/40/17 is what I run.
215/45/17 will give a larger diameter - you can check by using a tyre size calculator eg. Alloy Wheels for Cars, Motorhomes, Vans & 4x4s: Best UK prices with TYRESAVE

mattjbvfr

oops try again!
TYRESAVE: Tyre Size Calculator

timmccr

Subaru/Prodrive specified 205/45 R17 on classics.

Most people run 215/40 R17 due to better selection.

New-age cars run 215/45 R17 on standard Subaru wheels (standard WRX wheels at least (17x7), some 17 inch STi rims may vary (17x7.5 for instance)).

imprezered

Thanks guys,

Will go for the 40's.
Cheers
Mick

TonyBurns

iTrader: (3)

205/45/17 or 215/40/17 on a classic

Tony

EddScott

I've got 18s on mine and have been thinking for a while I want to go back to 17s.

Just doesn't feel as "chuckable" as it was.

totalllama

01 Bugeye here with 215/45/17 Yoko S306. Hold nicely on the standard alloys.

Cheers -J

young'n wrx

does anybody know if 205/40/17 fill be ok on 17's on a classic?

TonyBurns

iTrader: (3)

You can run them but your speedo will be inaccurate (more than running 205/40 or 215/40 it will underread i think (ie says your doing 30 and your doing 36 for example), so its best to sick to 205/45 or 215/40.

Tony

Triggaaar

205/40/17s will have a smaller circumference than 205/45/17s, so with the 40s, you'll be going slower than your speedo says.

D'man

My wheels came with 205/45/17's from the main dealer, so I've always stuck with that size.

timmccr

205/45/17 is the closest possible to the original rolling diameter of the 205/50/16 that most Imprezas came with. Thats why they were fitted to cars such as the RB5/P1 that all came with 17 inch rims as standard, or cars with optional extra wheels (i.e. my MY99 Turbo2000 came with 17 inch Prodrive ST2s from the showroom, fitted with 205/45/17).

The differences between 205/45/17, 215/40/17 and 205/50/16 are pretty small though, barely noticable between sizes.

Hoppy

215/40x17 is virutally identical to OEM tyre diameter and there's much more choice, eg Goodyear F1. Good rubber will make more difference to handling than just about anything else.

Richard.

Graphite

My speedo was under reading by 10% with standard 205/55/16s on checked with a mates GPS.

So I went for 215/45/17s to get a bit closer to reading true speed

G

Hoppy

Speedos are designed to always under-read a bit, just a little safety margin. The % seems to vary with speed. My classic with 215/17x7 does an actual 122 GPS timed at an indicated 130mph.