I guess how many hours running you can get would be a better gauge as mileage has too many variables, I can run the 700 for about 2 1/2 hours before I need a fill the 500 can run about 4 hours before it needs a drink. This is based on equal terrain and conditions easy going not hard working like pulling trees out or towing the trailer or the disc to till the ground.
2011 Sportsman 500HO.Front & rear bumpers, 2-up box.winch,26" pxt tires,windshield,gun boot,plow, heated grips & thumb, heated seat.
2003 Sportsman 700 twin.Front & rear bumpers,front spring adjuster,26" mudlites, 2-up box, HID lights,3500 lb. winch, gun rack,plow,hand guards.