Obama announces fuel standards for big vehicles - Yahoo! News
Who thinks that is do able?
I am not a semi truck operator or maintainer, is 23% more possible?
Those trucks get like 8 to 10 mpg and I am sure owner operators employ what ever tricks they can to improve that even if you only pick up .5mpg or 1mpg.
My guess is it would largely be aerodyanmic improvements.
When I moved from virginia to newmexico I hauled 6,000lb of stuff and towed my 3,600 lb car on a trailer. I got 8mpg, then had to drive the truck 50 miles to return it when empty. I still got 8mpg.
Heavy duty pickups having to get 10% better fuel economy is not challenge. That can be done easy, with out touching the engine its self such as with conversion to electric fans, different tires or gearing.
Fans alone or gearing alone would net +10% easy.
15% more fuel economy from a diesel pickup could be had with different tuning alone, no challenge what so ever.