We put the new Toyos onto our Blazer that had already run the bigger 40x15.50R20 Open Country M/Ts. It came as no surprise that the traction of the 40x13.50R17 was similar to that given by its bigger brother. We did notice that the skinnier tire tended to track a little bit less, both in the dirt and on pavement, and they seemed to grab a bit better on climbs. The load range “C” tire definitely flexed more easily under our 5,000-pound Blazer, but the few-pound-lighter weight difference was negligible. Without question, the 40x13.50R17 was better for our truck (than its bigger brethren) in every way, but we have to admit that we liked the look of the wider 40x15.50R20 tire.