For highway driving, in most places, aerodynamic drag is far more important than weight. I get nearly the same gas mileage towing a 1.5k kb ATV trailer as my da

For highway driving, in most places, aerodynamic drag is far more important than weight. I get nearly the same gas mileage towing a 1.5k kb ATV trailer as my dad gets pulling a 7.5k trailer. The frontal area of both trailers is roughly the same. They both need about 150 horse power to tow at 70 mph.