[farbmw]

Why do you need 17" to run on the track and not 18s, 19s, or 20s?

I know you need rubber that grip on the track, but do you need to run 17s?

[BDMBimmer]

You can run whatever you want to. I think why most people run 17s is the cost, if your going through a few sets a season than the 17s will be much cheaper to replace.

[farbmw]

Originally Posted by BDMBimmer

You can run whatever you want to. I think why most people run 17s is the cost, if your going through a few sets a season than the 17s will be much cheaper to replace.

So it is a cost and not a performance issue

[zuluZero]

Originally Posted by farbmw

So it is a cost and not a performance issue

I'm told by my track-buddy that it's also a performance issue. The extra sidewall has a couple advantages, including:
- some flex which aids traction - it can absorb some surges in torsion - acceleration/braking.
- some more cushion, to protect the rims and absorb some of the vibrations from tack hazards and coping.

[ctgazer]

Originally Posted by zuluZero

I'm told by my track-buddy that it's also a performance issue. The extra sidewall has a couple advantages, including:
- some flex which aids traction - it can absorb some surges in torsion - acceleration/braking.
- some more cushion, to protect the rims and absorb some of the vibrations from tack hazards and coping.

this.

mainly the cost option. track tires are just as, if not more expensive than a set of summers. treadwear rating is usually around the 100-80 mark which means the compound is extremely soft. depending on the track you frequent, itll run your tread down a lot. tracks like shannonville, dunville, which have more hard turns, and hard braking wear away your tires more than mosport.

[jeho]

Originally Posted by TrackRat

Many people like to use 17" wheels for autoX because of the slightly lower flywheel effect of the smaller wheel diameter. For actual track driving vs. autoX many people tend to go with larger diameter wheels and lower profile tires because they provide more grip - in general due to less tread distortion.

There are many variables and considerations including cost, size availability, clearance issues, etc. Quite frankly any of the tires that fit properly can provide plenty of performance and fun so there is no absolute reason to go to a specific size wheel/tire unless you desire to do so.

17" is restricted in tire width sizing...

Most hardcore autoXer who had been using 17s now moved up to 18s simply because of more tire choices in brand and sizing to fit your wide wheels...

for autox, wider is better, much much more grip...its proven...

[marcvtec]

17's for cost factor,
but a nice light set of 18's with sticky oversized rubber will out perform them,,,
18's are actually ideal for speed and handling, 19's too much 17's too small
I have tried them all in many cars FYI,
but again depends on your tack driving.

[Oulixes]

Formula 1 tires have been mentioned. Just for the interest sake, Bridgestone, the sole Formula one tire supplier is pulling out by the end of 2010 season. Two new companies are considered, namely Michelin and Cooper Avon. In addition to these two, Pirelli, one of the Formula 1 legends, announced they will present a bid by May 9 to offer Formula 1 tires. The bid will be presented at Formula 1 Gran Premio de España Telefónica, Circuit de Catalunya.