The easy alloy wheel thread (setups,offsets, brakes & al

[billinjah 0]

brembo 305mm ibiza brakes

porsche 5x130 bbs rs rims

front 7"

rears 7.5"

rear et 0 for shows and 6 for go's!

front et 4

195 45 16 all round although rears soon to be 40 profile (maybe!)

[iow_corrado_g60 0]

cheers lads i originally started this a while ago when i was looking fior a 2nd set of alloys keep em coming and ill update when get home thanks for everyones info im sure this will help someone

[jonrb 0]

There's something I don't understand about up-sizing the wheels and tyres.

 

Everyone who is running 16's seems to be running 205/45 R16 but the various tyre calculators show 225/40 R16 as having a closer rolling circumference to the standard 205/50 R15.

 

Is it a case that in the real world 205/45 R16 is more suitable than the on-paper figures would suggest?

 

Tyre Size Comparison

Tyre code   Diameter  Circumference  Difference
----------  --------  -------------  ----------
205/45 R16  591 mm    1857 mm         0.84 %
215/40 R16  578 mm    1816 mm        -1.3 %
225/40 R16  586 mm    1841 mm         0.07 %

 

Sorry to resurrect an old thread, but I'm moving nearer to making a purchasing decision and could do with an answer to the above.

 

Forgetting about 225/40 R16 as I haven't seen anyone wearing those, I notice that a lot of people mention that 16's can be run as 205/45 R16 or 215/40 R16

 

It seems to me that if you're keeping the same width and rolling circumference (ie. 205/45 R16) then you're not going to gain much of an increase in contact patch, whilst the increased width of 215/40 R16 suggests an advantage.

 

And yet a majority of people seem to wear 205/45 R16. Why is that?

 

Edit: Is it because 205/45 R16 is a closer match to the rolling circumference of the original 205/50 R15? It seems to be +0.8% for the 205/45 R16 and +1.3% for 215/40 R16. But if that's the case then why not 225/40 R16 on 16x7.5 which is only a 0.07% difference?