scooter(WRX03 PPP)

Is there any problem with having the following configuration on my WRX as a temporary measure:

Front Tyres 225/45/17
Rear Tyres 215/45/17

I realise that if anything the wider tyres would probably be better on the rear, however is there any danger of upsetting the 4 wheel drive system?

I also understand that by changing to 225's, the actual speed against what the speedo reads will increase too by 1-2 mph, so if I have 225 on the front and 215 on the rear, what would the effects be.

Last question, I know that on 225's, the top speed of the car will increase by a small margin, but will the accelleration times also decrease?

Thanks.

pete higham

your speedo shouldnt change because there isnt any differance in the size of your tyre walls.

its your tracking that will be out so you will get uneven tyre wear

i think, i stand to be corrected

scooter(WRX03 PPP)

Hi Pete,

Not cruising down deansgate today? lol

Apparently even though the other figures are the same, there is still a difference in the size of the tyre walls and that's why there is a small change, but only 1 or 2 mph at most. I was also thinking that tracking might be out. Funny thing though, the damn car has never felt this good. I got a good deal on some P6000's (but only 2), so stuck them on. My 2 back tyres still have some deep tread so decided not to get an additional 2 just yet.

Fizz

iTrader: (1)

I thought having a mix like that will totally screw the diff's up as you have a different rolling radius on the two axles...

TimmyboyWRX

you are right, there is a change in the size of the tyre walls, remember that the first number (215, or 225 etc..) is the measure of the width of the tyre, the 2nd figure ( 40 or 35 etc..) is the height of the wall as a %age of the width, hence 225/40 would be bigger than 215/40 as 40% of 225 is larger than 40% of 215... the 3rd figure ( 17 or 18 etc..) is as im sure you are aware the size of the wheel diameter the tyre will fit

confusing isnt it! lol

scooter(WRX03 PPP)

Ooops, I'm worried now.

scooter(WRX03 PPP)

So I guess that as the diameters are different, then this is no better than having your scoob towed away on 2 wheels.!! ****. I need to get 2 more tomorrow then.

TimmyboyWRX

actually having said %age im not not sure im right lol its getting late, it is certainly a ratio of the width anyway, meaning yes one et of tyres has a larger rolling radius than the other.

But id not worry mate, scoobs come with space saver spares and no rules about distance to run them on, the diffs should cope fine with that minimal difference in tyre size, i mean its not really any different to fittin new tyres at front of back and having worn ones on the other axle, youl be fine, dont replace unless your really worried or really can afford it id say

Hoppy

The 225/45 tyres are about 1cm wider diameter than 215/45, as well as being 1cm wider width - about 1.4% different.

These are the downsides:

I don't know what the diffs will take, but it can not do them any good. Speedo is the least of your worries.

I would also be concerned about the handling, as the front/rear balance will obviously be affected. Would fail an MOT I'm pretty certain.

If you're talking about a Classic shape, 225s will rub on the rear.

Fitting cheap tyres on a high performance car is foolish and false economy.

Upsides:

There aren't any.

Richard.

PS Space-saver spare has same rolling radius as standard wheels.

scooter(WRX03 PPP)

>If you're talking about a Classic shape, 225s will rub on the rear.
>Fitting cheap tyres on a high performance car is foolish and false economy.

Thanks. Mine is a Newage an so 225s are not a problem. P6000's are not cheap tyres, but as I don't want to take a chance on the diff, I'll fit another pair. It's a shame to waste the other 2 though as they've got lots of tread left.