Tyre width choices please help!!
21 October 2016, 01:30 PM
#1
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Tyre width choices please help!!
Hi there I have a set of 7.5 inch wide revolution s they 205 40 17s but they look to thin for my liking my options are 215 40 s ,235 40 s or 225 45 s.
Any body run any of these sizes on 7.5 inch rims ?? Or have any pics so I can have an idea of what theyou look and feel like ??
Cheers
Car is a v3 type r
Any body run any of these sizes on 7.5 inch rims ?? Or have any pics so I can have an idea of what theyou look and feel like ??
Cheers
Car is a v3 type r
21 October 2016, 04:53 PM
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No 205/45/17 would probably be the right size but its a horrid size to get hold of so most people go for 215/40/17 as they are much easier to obtain.
On a classic I would not go any wider than 215 or you may have issues with rubbing.
On a classic I would not go any wider than 215 or you may have issues with rubbing.
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23 October 2016, 11:59 PM
#8
To put some numbers to it:
OEM 205/50 R16
= 1921mm rolling circumference.
For a '+1' 17" upgrade:
205/40 R17
= 1872mm r.c. (2.5% difference)
215/40 R17
= 1897mm r.c. (1.2% diff.)
best overall choice
205/45 R17
= 1937mm r.c. (0.83% diff)
closest to OEM
215/45 R17
= 1965mm r.c. (2.3% diff.)
OEM 205/50 R16
= 1921mm rolling circumference.
For a '+1' 17" upgrade:
205/40 R17
= 1872mm r.c. (2.5% difference)
215/40 R17
= 1897mm r.c. (1.2% diff.)
best overall choice
205/45 R17
= 1937mm r.c. (0.83% diff)
closest to OEM
215/45 R17
= 1965mm r.c. (2.3% diff.)
24 October 2016, 01:30 PM
#9
They also got 2.5 engines and different ratio gear boxes, but don't let that stand in the way of justifying incorrectly sized tyres 
A percentage difference of 2.1% is not recommended. Recommending a 45 profile on a 215 is just plain wrong stating the speedo would remain unchanged. 
A percentage difference of 2.1% is not recommended. Recommending a 45 profile on a 215 is just plain wrong stating the speedo would remain unchanged. You've got 25ish gear sets to go through now, to check none of them were used in the US and Australia, as well as JDM.
I wrote that the speedo would read 'exact', which it does. As opposed to reading 'over' which is the case on a 205/50 x16.
On uneven roads, like here, there's a performance advantage in a more compliant tyre, hence my suggested increase in aspect ratio.
Last edited by 2pot; 24 October 2016 at 01:42 PM.
