[PSYCHO-FREEP]

The whole reason for running diesel engines in the first place is POWER. The torq delivered in a diesel cannot be duplicated by a gas engine. Which spells towing capability. It is not horsepower that gets that 60,000 pound load to the top of the mountain, it is Torq that does that. And diesel engines are the only means to produce that kind of torq in an extremely efficient form.

Diesels deliver over 3 times the torq of a gas engine; Especially NG engines. That is because of the combustible nature of paraffin based fuel. (Cetane ratings)

This whole hype will prove to be a great error.

[thackney]

Mercedes-Benz delivers first natural gas Econic semi
http://green.autoblog.com/2010/01/01/mercedes-benz-delivers-first-natural-gas-econic-semi/

[Errant]

Energy content of fuels role.

Fuel	BTU/Gal
Gasoline	125,000
Diesel	138,700
CNG	90,800

Engine efficiency plays a major role.