Red Stripe, I travel over many of the same roads as you and see about the same efficiency. The hills you have to go over and the wind directions are likely the issue. Unfortunately, the only alternate routes for your commute are not comparable in speed. After 18+ months of driving those hills at 65+mph, I average 3.0-3.2 miles/kWh. I also see the variation in efficiency with direction, and I believe it is related to the primary wind directions on that path. For me, the trip home is more efficient (generally a tailwind).