i went to my local tyre plac today and asked for 215/40/17 for the front and 235/40/17 for the rear.. he told me that there would be a 16mm diffrence in height..i was going to ask him why but there was a massive cue..so can anyone on here tell me if its true and if so why..

 

The sidewall profile is proportional to the width of the tyre. Even though they are both '40', the 235 is taller than a 215

 

Of course they will be a different height, you would need a lower profile on the rear with that width tyre.

Steve.

 

235/40/17 - 40% of 235mm = 94mm
215/40/17 - 40% of 215mm = 86mm

Difference of 8mm IMO!!

Big enough to look daft & put the speedo readings out.

245x35x17 would be better @ 85.75mm.

 

If you are on a 7" rim, I wouldn't put anything more than a 215/40 on. If you are 7.5", then 235/40 will be fine, and the combination you are talking about is what I used to run on my 500bhp Sapphire. I wouldn't fit a 245 unless you had a MINIMUM of an 8" rim. The disparity will be no problem what-so-ever between a 215/40 and a 235/40 tyre on a 2wd car. Obviously if it is 4x4, then the rolling radius HAS to be the same .

 

Mike im going to be running..

front: 17x7's with 215/40 or 215/45
rear: 17x8's with 235/40

should this be ok

how can tyres be so hard to choose

 

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

according to this, 16mm difference

 

Perfect choice IMO (but NOT the 45 profiles on the front, you will have clearance issues on the damper), as it raises the height at the back to give the a nice noise down stance, which aids turn in .

 

Yep, 8mm at the bottom of the tyre and 8mm at the top of the tyre, but will only increase the ride height by 8mm.

 

you will NOT notice 8mm and if anything it will correct the speedo as they always read well low anyhow!

My Chaser has 215/40s on the front and 235/45s on the back, looks normal, can barely notice, cant even really tell the difference from when it had 215/45s on the front either.

Its a RWD car, your meant to have bigger tyres on the back, its not as if you got big balloon drag slicks on the back

In near future i might go for 17s on the front and 18s on the back actually.

 

iv made my mind up to go for

front- 215/40/17

rear- 235/40/17

thanks for the input guys..

i was thinkig 8mm wont be noticable at all

 

ride ieght yes, but i think rsford was asking about the height of the tyre itself and that was it as much as that

8mm is hardly noticable, it's the difference between brand new and drifted to fook tyres really

thing is, will they fit in the arches without fouling as i saw nutters car wearing 265's and he had most of his arch cut away

 

Here you go, 245/35x18 and 285/30x18, id be damn sure thats a fair different rolling radius isnt it?

And heres a side shot.



People worry about stuff like that too much.

If it fits, fit it, simple as.

 

other people on here have 235/40/17 on the rear with no rubbing unless theres a full load..my car never has more than 2people init.

 

not even noticable

 

Cos they are stretched so much you can't see the height difference.

 

Stretched or not itd make bugger all real odds.

Ferrari F50s run 245/35x18s on the front, and 335/30x18s on the rear, a MASSIVE difference, do they look wierd from a side on profile?

Do they fuck!

 

.....on 18" x 10" rims!!!!



You're not going to notice fuck all difference there mate as theres 0.25mm difference on the top & 0.25mm on the bottom of the tyre!!!

 

What about the F50 then? Or my Chaser one?

The Ford world is well retarded with regards to tyre sizes IMO, people worry too much.

Simple fact is nobody would notice an extra 8mm, thats tiny.

 

......for some blokes that little bit extra would be a bonus!!!

 

 

never realised the width affects the profile hieght

 

why does it look like you've banana'd it round a lampost stav?
the front wheel seems to be too far forward and the rear seems to be too far back

or is it just camera trickery?

 

The profile is a % of width, so on a 40 profile tyre, every 20mm extra width is 8mm on each sidewall, and hence 16mm difference in overall diameter.

 

No camera trickery and the car is straight as an arrow.

Too many suplex's have affected your mind I reckon mate.

And the fact the arches were quickly flared so are a different shape to stock.

 

i see what he means, it looks like you have a nice load of toe out on the rear and toe in on the front.

 

maybe the front wheels are straight?

that would cause it to be desiving

 

or it could be because of the light flashes on the wheels. on the rear wheel the light is shining on the left but the front its shining on the right.

thats probably why.

 

yh maybe