The clowns who installed my Carli lift and Toyo tires can't follow their own work order...installing four Toyo AT2 35x12.5R18 F Load tires instead of five, to replace my LT275/70Rx18E BSW A/T's on the factory 18" rims. So in the event of a flat my spare will be traveling 5% less far than the other side. I originally planned to return for a new Toyo spare but started thinking...5% is not a lot, and by applying excess pressure in the spare the diameters should be even closer. I'm thinking with a damaged tire in Grand Staircase-Escalante National Monument it would be prudent to drive to Flagstaff, potentially 400 miles, to a trustworthy tire dealer. Flagstaff is close to my home base in Sedona and that return trip could be one day instead of two (with a stop in God knows where for God knows what replacement tire). Any opinions on just how much wear 5% represents on a differential??? How about a return trip from Montana...pushing it too much?