Replacement tires -1 size bigger on stock 06 18s?

[RamAirfreak98ss]

My dealer had a set of 275/70/18 Cooper discoverer ATRs...

Everyone says get the M&S for the most snow traction, but they dont come in 18s or bigger..

I saw a lot of you guys with the 18s get a 285/65/18 i think or 295s...

What is the next size "wider" by a hair tread wise? Are these cooper stock size 18s going to be a little wider tread pattern than the stock continental contitrac TRs anyway? I want the most snow traction possible as im probably going to get Nitto Dura Grapplers "highway type tire" on the ford stock 20s for the rest of the year.

Only need these grippy tires for plowing in the winter from Dec-mid march.

[choctaw]

Check this link....you can enter the size and it will give the measurements and you can do several at a time and compare.

Tire Size Calculator - tire & wheel plus sizing