I'm looking to buy a used fleet Cascadia in August. I'm set on a DD13 and 10 Speed. I drive at nights usually starting my day 22:00-00:00 and typically cruise at 60-61mph but I want the torque capability of pulling hills without dropping down to 50mph like I do in my company truck (International, Cummins, 10 Speed, no clue on gear ratio). I will typically be running southeastern states from VA to FL and out west to Texas.
I've tried researching gear ratios and it's nothing but mixed opinions when it comes to fuel economy. I figure I wouldn't suffer from a higher gear ratio since I cruise at 60 and can still pull hills.