On a 1996 Explorer, we currently have some larger 'off-road' tires that came with it. If we switched to standard 'highway' tires, would we likely get better fuel mileage?

90% of the driving is on the highway for this vehicle.

thanks,
Bryan

 

The size of the tire may or may not effect the fuel mileage. It is a power to RPM issue.

The best way to help with mileage via choice of tires is to pick one that has a low rolling resistance. Consumer Reports just tested a bunch of SUV tires using a 2004 4x4 Ford Explorer. They rated the rolling resistance (along with many other performance standards) of a bunch of different tires.