So I’m planning on getting new tires pretty soon for my Z Track. I doubt the re040 will last long during lapping sessions. Even in poor (ie slow) conditions at MidOhio, the rear where quickly getting greasy.

The OEM tire size is 225/45R18 front and 245/45R18 rear. Unfortunately, selection is very limited in that tire size. I haven’t found any competition tires that match this size. I did find the Michelin Sport Cup in 225/40 and 235/40. But this would change the diameter 3.4% front (not too bad) and 4.8% rear (almost a full inch!). Stagger will not be affected much (~1%)

It should reduce the under steer. Apart from a bumpier ride, should I expect any nasty surprises?

A note, I’m more interested in car balance and tire stability under heavy load than ultimate grip. And I don’t want to change wheels just yet. (I need a kitchen table before that!)

Thanks for you input.

 

The tough size to get is the 225/45/18. I would put a 245/40/18 in front and a 245/45/18 (stock size) or 255/45/15 in back. The two back sizes are much easier to find. This would make the car more neutral handling. Less understeer. Don't know how you would feel about that. The 245/255 combo will fit well with the track wheels, and still maintain the stagger.

Lou

 

On track model wheels, I'd get

245/40-18 front (also 235/40-18)
255/40-18 rear

I think for lapping, a 40 sidewall on these tires is better.

Check out the new azenis RT615



Selection is wider in 17"