Tire type/quality vs sizing?

[INTMD8]

I'm at the point where I need to buy some tires. I need them to be close to 29in tall so they look correct on the car (57 Cadillac). It will be around 5000 pounds and utilizing a Roadster Shop chassis with front/rear sway bars.


It's not going to be raced but handling is definitely a concern.


This is what I'm considering.


Michelin Pilot super sport


Front- 245/45/20 28.7 diameter


Rear- 315/35/20 28.7 diameter


Now I would rather not have so much width difference between the front and rear but these are the only 2 tires in this model that are enough/same height.


I could tighten up that difference by using Continental Extreme Contact DWS.


Front- 255/45/20 29 diameter


Rear- 295/40/20 29.3 diameter


Any thoughts on this? I'm thinking that even with less than ideal widths the car might still work better on the PSS's over the DWS's of what I consider better sizing.

[RSX302]

Horsepower? Typically larger rear widths are to help hook power.

With 5000lbs, you can't be wide enough at all corners.

I would lean toward the DWS..even with the 500utqg rating. I'm thinking you may need the higher treadwear to make the tires last during more aggressive driving. You are in large suv territory.

[RSX302]

Edit: Sorry..Operator error with iPad

[dontlifttoshift]

Performance aside, the super sports are quiet and ride really nice.

With two turbos up front and what you intend to use the car for, I wouldn't sweat the size discrepency.

[INTMD8]

Thanks for the input guys. Good to hear the PSS is an nice driving tire.

Being a turbo car power will be adjustable, conservatively 550-750 at the tires.

[Quickboat]

The DWS's ride really well but have snow capability which compromises cornering a bit. I run them on my DD since I see surprise snow every once in a while (and the 4x4 truck is at home) this prevents me from being caught running a summer tire. I love the DWS's dont get me wrong, great compromise, but if you will never see snow, maybe look into the DW's or a summer tread.

[INTMD8]

Yeah I wouldn't normally be looking at an all season tire but it just so happens to be in what seems to be good sizes.

Another idea is to just run PSS's in 255/45/20 all the way around. From what I'm reading that particular tire runs a bit wide in comparison to sizing so I may not even be able to fit a 315.