*Sonic*

Apart from visually

what is the difference between using 215/40/17's against using 215/45/17's ?

Ta

Simmo2

Sonic

Depends on car

New age: 215/45/17
Classic 215/40/17

I believe on the classic the 40 profile offers only a 1% difference in original size hence only a 1% difference for speedo
whereas the 45 is about 9-12%

Hope it helps.

Try the Toyo website they have a conversion table for upgrades


Pete

*Sonic*

Cheers

But didnt the P1 come as standard with 215/45/17's

Im not bothered about the speedo reading as I can compensate for that, im more interested in handling characteristics

Steve

ozzy

The P1 came fitted with Pirelli tyres and they only did them in 205/45/17's. Pretty sure it was the same Pirelli's that had been on my RB5.

So your choice is 205/45/17 (and a limited choice) or 215/40/17.

Haven't heard of any others being fitted in 17's.

Stefan

dosenöffner

Lower profile is better for road handling. Less wall flex.

Here is a link for speedo correction.

Tire size calculator

ozzy

As far as handling charactaristics are concerned I didn't really notice any difference between the two sizes and I don't expect anyone else too either.

It's not a like-for-like comparison since you have to change tyre manufacturer, compound and tread patterns going from one to the other. Too many variables to judge purely on the dimensions IMHO.

I'm sure more experienced folk could make an educated guess given the sidewall and tyre width differences, but it would be a guess unless they've actually driven a car with both sizes and the same tyre design.

Stefan

ozzy

The sidewall flex is a prime example. Of course, a smaller sidewall should be stiffer, but just "how" much stiffer depends on the tyre design.

Perhaps a Goodyear 40 profile is much stiffer than a Pirelli 45. Or perhaps a Toyo 40 profile has more flex than the Pirelli. Who knows

I've personally went through

Pirelli 205/45/17
Goodyear 215/40/17
Toyo 215/40/17

Out of those 3 tyres I prefered the Goodyear, but I'd put that down purely on the tyre compound rather than it's size. It was only the wet weather handling of the Pirelli's and Toyo's that I hated.

Stefan

dosenöffner

Because you are the best? I prostrate myself before you.

Try Yokohama. They make a nice tire with good performance vs. wear characteristics.