Re: Tire wisdom, please

Jeff Roberts

To add to what Hal said…

DWS example, there are 4 16″ sizes available with a measuring rim width of 7″, which is: [i]the industry standardized rim width upon which the tire must be mounted in order to confirm it meets its dimensional targets[/i]. This is what Hal means by “too wide will move around on the rim.” Stick with a tire with a measuring rim width that matches your rim width.

Of those four tires, the 205/45/16 is the smallest diameter = more revs per mile. This effectively raises your rear diff ratio without taking the point hit.

This is good for autocross. If this is the way you want to go, looks like the Conti is your only choice in that size.

On weight, it is a good thing to consider as well. I believe the general understanding is, one pound of wheel/tire (unsprung weight) is about the same as 8-10 pounds of sprung weight. Our classification system does not consider wheel weight = free weight savings. My stock wheel/tire combination weighs approximately 53# per corner, but what I run for a/x is approx 42# per corner. Do the math. 🙂

Treadwear ratings are only comparable to tires by the same manufacturer. A 540 rating on a Conti does not equal a 540 on a Bridgestone or other make. This number is pretty useless other than to compare a 500ish to a 100ish, obviously the 100ish is a stickier tire. But, a 140 on a BStone compared to a 180 on a Conti doesn’t necessarily mean the Conti isn’t as soft or will last longer – too close to compare like that.

Tire Rack has a boatload of tech information on their site: