215/45/17 ???

st10587

i only brake for cake!!!!
Oct 4, 2007
3,669
0
Hindhead
i know some have 215/40/r17 whith out issues. is your car lowered? you would probally get away with a 205/45/r17 just but it will throw you speedo, trip computer etc out
 

Fl@pper

Back older greyer and less oilier but always hope
Jun 19, 2001
12,368
25
Gloucester
not by anything you would notice if any as thats only a 5mm difference in height.

5% of the width not 5mm - but it will be minimal for sure


205 = mm width

45 = % of the width (profile)

17 = rim size

letters in between for speed ratings blahblahblah
 

Fl@pper

Back older greyer and less oilier but always hope
Jun 19, 2001
12,368
25
Gloucester
:doh: i stand corrected but im glad i know that now. :hide:

lol sorry it's a common misconception but you are right it's very minimal really

i have 215/40/17 on my cupra wheels and i have no problems at all.

flapper is there any harm in doing this?

not so sure arch problem wise on your shape but what size you have before and after ?

http://www.miata.net/garage/tirecalc.html

try that ^^ will give you exact differences and at the bottom will state speedo inaccuracies


reading up for example

205/40/17 >>>> 215/40/17

speedo will be 1.3% too slow with a sidewall change of 82mm -> 86mm

as said above minimal differences between the two really so shouldn't see any issues


gone up a profile on standard rims myself as i was fed up of all the damn potholes round here ripping the 17's off the rim
 
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NickyJam

FR - gone, not forgotten
Mar 17, 2008
1,668
0
SW LONDON
i'm gonna stick 215/45 17's on my FR in around 2k miles time (may even go with 215/50)...the 45's should fit no problem and no rubbing as they'r only 7.5mm wider each side, therefore, the difference in actual tyre "size" is minimal. the 50's are more noticeably larger and will need to have a butchers before making a decision as to whether to go for them.

benefits should increase a tad though with either :thumbup:
 
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its not me and from what ive read cupra 205 40 17 to 215 40 17 just wondering if that would give so much movement in the same way as bigger sidewalls. also is it legal or is it just the opposite to tyre strech but in the opposite direction as i beleive theres no written law to that either?
 

NickyJam

FR - gone, not forgotten
Mar 17, 2008
1,668
0
SW LONDON
its not me and from what ive read cupra 205 40 17 to 215 40 17 just wondering if that would give so much movement in the same way as bigger sidewalls. also is it legal or is it just the opposite to tyre strech but in the opposite direction as i beleive theres no written law to that either?

it's truly minor difference in sidewall size...and no it's not illegal, however, if it becomes drastically fat then obviously that could be potentially hazardous. i say this as the old Merc's A-Class have 15" rims with pretty fat sidewalls

anyone correct me if i may be wrong though
 

Fl@pper

Back older greyer and less oilier but always hope
Jun 19, 2001
12,368
25
Gloucester
try the tyre calculator above for size differences when swapping wheels/tyres and i have always found (as on the other thread) it's the radius to the rear sill edge that seems to be the smallest measurement in the arches and therefore the most important one to watch

take a look side on and you will see what i mean and measure the current gap you have and any changes you make make sure you allow room along the rear beam axis for safety

and when you do run em closer - watch ya knuckles when you fit a wheel or ever spin it to check pads/bearings :):)

(lost a few knuckles myself)
 
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