I have the Chevrolet 2500 HD crew cab. Nothing on the bed. I upped tires and adjusted for size on my tuner. I was shocked that I had better fuel mileage at 75-80 mph than I did at 65-70.
I did use a sheel of plywood to make a Portuguese bed cover for the airflow and to cover my stuff in the bed...
I used to hand calculate my fuel mileage on my LLY Duramax. I averaged around 24mpg on all highway runs and 18-19 for all other driving. I would have thought the 3.0 liter 6 would have done better.
My last hand calculated fuel mileage run was done last year. From RI to central PA. Doing around...
Yes, I agree BigR. We both know you could give the media a typed article and they would still get it wrong. Lol
My 2006 was an LLY. Just a detuned LBZ, but has all the LBZ goodies inside. Just basically a tuning difference.