Had to make a trip from Va to Atlanta last weekend to move my son home, needed my 14' utility trailer, just purchased a 2011 avalanche(had a 05 years ago and loved it) only had a week before trip, anyway hit the road and trailer pulled like crap on the highway, I knew it was heavy, thick wood floor, but single axle. Had never towed with this before so ???, anyway just felt like was dragging a chute, even down a grade was bad, was watching the instant fuel mileage and was real bad...I'm thinking should have driven the duramax. talked to my other son at lunch stop, he said noticed the same thing when he towed it on the highway, said try dropping the tailgate down. Figured being mesh how much could that hurt ??? well at next fuel stop, dropped the gate inside, instantly felt like you took parking brake off !!! picked fuel mileage up well over 5 mpg !!!! would never though that !!!!! just passing this along...Rob

I towed a 15 Whaler with a diesel Mercedes SUV and had a similar experience! The boat felt like a parachute and mpg plummeted. Luckily it was only a 200 mile trip. With my duramax I didn't have the same experience, maybe pushing a brick through the air first didn't affect it as much

never thought of that...good idea.will have to try that on next long trip with mine

I used to have one of those too. I found out the same thing and couldn't believe how much that gate sticking up in the air dragged things down.

feels like you have a chute open !