@Dean

I seem to have very little front end grip in the wet. On medium throttle the front end washes out all over the place, it's a bit better on the power but can get a little too entertaining. I know I've got crap tyres (Kumho Ecsta 215/45/17) but was wondering how much improvement I can expect from something like Toyo's. Any advice on size, make, dealers or prices would be great. Cheers.

Fosters

Shouldn't that be 215/40 zr 17? not 45.

Eagle F1 (I have these and they're much better than pzeros), Bridgestone SO2/SO3, Toyos. are all commonly used tyres on this bbs.

@Dean

Yeah I noticed everyone seems to use 40's but it came with 45's on it..

Fosters

Your speedo will be (more than before) inaccurate with a larger rolling circumference.

carl

And your gearing will be slightly taller, too (car travels further for each revolution of the wheel).

@Dean

Ok, switch to 40's it is (205 or 215). Am I the only one with the grip problem though ??

2Scoobysnacks?

Just put 4 toyo's on, and no more front end ice skating for me

Fosters

205/45 zr 17
215/40 zr 17

carl

Or 'add air' to the end that needs grip (I know it sounds counterintuitive, but apparently it works). I run 34psi front 31psi rear, but that's on 16s.

Otis

I spoke to Subaru this week about this and they say the tyre size for the Impreza should be 205/45/17 and not 215/40/17.

To calculate the rolling distance of 205/45/17 it is:

(205 x 0.45 x 2) divided by 25 and than plus 17 = 24.38

The 215/40/17 = 23.88

I have just moved onto 17" from the standard 16" which work out at 24.20. Therefore the 205/45/17 at 24.38 are nearest to the 16".

The down side however is the Toyo, Goodyear F1 and co. do not make 205/45/17 tyres!!! The P Zero is the only real big name tyre in that range .

Anyway this is what I've been told over the last 2 weeks whilst looking for some 17" - it may of course be a load of 8ollocks!!!


Otis.

Lushman

OK I have just bought a set of 2ndhand alloys 17".
they came with Yokohamas A520 205/45 17.

Although I have order another set of tyres.(not Yokos).
would anyone recommend or not, going to 215/45 17.

Obviously the tyres are slightly wider but what effect would it have on the handling, can I expect it rubbing?

Fosters

Otis, you forgot to multiply by PI (2Pir)

therefore
circumference (mm) =
(((205*.45)*2)+(17*2.54))*3.1415927

@Dean

Apart from lack of grip I've had no rubbing problems with the 215/45/17 (Kumho 711), on road or track. This is on standard suspension though so I was thinking of dropping to 205's as I'll probably change the springs at some stage.

Andrew Timmins

Which Kumho tyre are you using. I have the 712 on 15" and they are suberb wet or dry. Much better than the Goodyear Eagle NCT2 or Firestones I've used. Run the front tyres at a higher pressure than the manual says, I use 35 front 32 rear for road and 39 front 35 rear for track. The car is absolutly neutral when on the limit.