Tire rolling resistance (copied from another forum).

[in2trux]

I get the low rolling resistance effect on fuel mileage BUT!, low rolling resistance tires in general are flat out dangerous when it comes to winter driving conditions.
We replaced Michelin XZA3 in January for Bridgestone 726 EL on the drives. Even though they still had 8-10 /32's. The 726 is a very good tire in deep snow.
One strategy we used years ago was running a VERY aggressive lug recap November thru March and switching back to "baloney skins" in spring.
You really need two sets of rims or the mount and dismount will eat the savings.

Even if you run the southern routes. I've threaded the needle between spun out trucks on Flagstaff hill,without chains with good lugs and that was worth any loss of fuel mileage.