My NV2500 with V8 on Regular Fuel at 6000ft carrying Appliance Parts to the ceiling averages Lowest 15mpg Highest 19mpg If I use mid grade my mileage will increase by 2mpg Not worth the added cost at the pump. FYI Got a nail stuck in my tire after 2 weeks of delivery. Stopped by a local Firestone Store to see if could remedy the problem, What a lousy business model. Says could'nt look at till tomorrow and you got nitrogen for air go back to see your Nissan dealer! WTF! Ok Firestone doen't want my biz. Remembered my last tire purchase at Costco and they also used nitrogen. Drove to the local Costco, explained my problem, manager asked if I was a member, he put it up on the rack, dismount the tire from the wheel and patched from inside. During the repair a crowd had formed wanting to know what vehicle that was? Truck or a van? Well any way to get to the crux Costco REPAIRED my FIRESTONE nail collector for FREE!! Yeah F'n FREE. KUDOs to COSTCO..