whats best ?

bb1boy · Post by **bb1boy** » Thu Mar 20, 2014 1:03 pm

A 215/45/17 will throw your speedo out though. I run 215/40/17's and mine is bang on.

Post by **RattyMcClelland** » Thu Mar 20, 2014 2:56 pm

Speedo innacuracy is such a minor issue. It's actually irrelivant imo. Tyre wall is far far more important. Imo 225/45/17 is best but is difficult to pull off sometimes.

Post by **Donald** » Thu Mar 20, 2014 3:16 pm

The difference between 215/45 and 215/40 is negligible though, 2.04mph at 60 and AFAIK the law gives you 10% either side of your displayed speed anyway (?) so that's well within tolerance. Obviously in the interest of accuracy I would rather a bang on speedo, but 2mph vs a better sidewall I know what I would pick.

andyjess · Post by **andyjess** » Thu Mar 20, 2014 5:33 pm

im with derrick 17ins look good on my 5th an they don't slow me down lol

Post by **RattyMcClelland** » Thu Mar 20, 2014 6:18 pm

Fir what's it's worth on a 215/45/17 at 70 I'm actually doing 67mph.

Post by **derrick1988** » Thu Mar 20, 2014 7:33 pm

big up the 17s with 215 45 17s!!!!!!!!! im only driving around central Scotland when I hit Monaco ill have a re think haha

andypont · Post by **andypont** » Thu Mar 20, 2014 11:41 pm

I run 17" for most of the year, but put my standard 16" sawblades on over winter.
The steering feels a little heavier with the 17s, and they make any damaged road surface more noticeable. That said, I do prefer the drive with those compared to the 16. It seems to stiffen up the handling and gives a more reassuring feel - even though the handling is fine with standard wheels. I also much prefer the look with the larger wheels.

This article on carbible is pretty good and worth a read. It has a calculator that will give speedo differences for different size wheels / side walls.
http://www.carbibles.com/tyre_bible_pg4.html

bb1boy · Post by **bb1boy** » Fri Mar 21, 2014 10:16 am

Fair enough about the speedo inaccuracies, at least you won't get done for speeding.
Are my maths right in as much as a 45 profile 215 tyre will be about one centimetre taller in the sidewall than a 40 profile? Does that 1cm really give a noticeable advantage? Is it just a comfort thing?

lxstuart · Post by **lxstuart** » Fri Mar 21, 2014 10:34 am

Near enough a centimetre (10.75mm to be exact)

Post by **Donald** » Fri Mar 21, 2014 11:48 am

Think less about the actual measurement because as you say 1cm seems like nothing, it's the percentage.