What's the performance diffrence between 215/40/17 and 215/45/17?

I cant comment on the Performance difference, but i have used 205/40 R17 the Standard size, & 215/40 R 17,  which are fine on a vRS

There is not necessarily that much difference in tread on the road, 215 is the sidewall width, some 205 & 215 are much the same size, total diameter and rolling circumference.

Brand dependent.

215/40 R 17 is the Standard size on the Twincharger VW Polo GTI,  Audi A1 185ps, & Seat Ibiza Cupra with the Same Engines and DSG.

 

215/45 R 17 is a bit big on a vRS, but some have had them fitted.

It will depend on the Brand and the actual size compared to the Numbers on the side.

 

http://kouki.co.uk/utilities/visual-tyre-size-calculator

Edited 4 August, 201411 yr by goneoffSKi

Not quite an answer to your question, however we have a Monte TSI running on Pirelli Nero 205/40 R17 and a Rapid Spaceback TSI with 215/40 R17 Dunlop Sport Maxx. Visually there is little difference size wise and they handle similarly out on the road, although the Rapid provides that bit better ride but due more to standard suspension rather than 'sport' on the Monte and a longer wheel base.

 

 

TP

What's the performance diffrence between 215/40/17 and 215/45/17?

In principle at least the 45 profile will ride better due to the higher wall height (96.75mm vs 86mm). Against this, the 40 profile should give more accurate steering. (all presumes you compare the same make and model tyre in the 2 sizes at the same pressure, on the same car. This is important because comparing a Furbie to a Rapid means changing pretty much everything in the suspension including vehicle weight)

 

The difference in overall rolling radius is only about 3%, so I'd be surprised if it made much difference to acceleration, braking or fuel consuption.

On the question asked the difference between 215/40 R 17 & 215/45 R 17 might be 3.5 % or so.  

In practice they can be much nearer identical in size between say Dunlops & Pirelli.

 

But if it is the difference on a Fabia vRS with Standard 205/40 R 17 to 215/45 R 17,

 the near 5% difference will be noticed by the DSG. Speedo & Mileometer.