High-Lo Range Gearing in trucks for better MPG

It seems that the average full sized truck is geared for torque and towing power even though most of the time most of us drive around with a empty bed or not towing anything.

In 4x4 trucks there is a low range gear box to help when you need lots of power.

Could the same technology be used to create a better gear ratio for increased MPG when not hauling/towing in standard trucks which you would then engage a 'tow' gear ratio when power is needed? But have better MPG on a daily basis.
Allen 09/10/2012
This is a good idea! it would solve a lot of problems!
Aaron M 09/06/2012
Great idea, 2 different trucks available at Ford. 1 with the usual Low & another with highway gearing. In normal mode trucks would be identical