3-cyl engine into a compact truck?
 

I guess you all might know the Triumph Rocket III Roadster, with its 140cu.in. straight-3 engine.
http://1.bp.blogspot.com/-Y9pTRRUgXm.../Photo1085.jpg
Since its 163lb.ft. torque peak is surprisingly achieved at a lower engine speed than the 154lb.ft. in the Duratec 23NS formerly used in the Ranger, would the 3-cylinder engine layout be a reasonable option into a compact truck?

its not too bad but not as good economy as say using a 1.9 tdi which makes its max torque 150lb to 180 ft-lb at 1900 rpm.

My thought is that triumph motor has good torque and hp which would be nice for a trike or anywhere lightweight is needed like say a stream liner.

The point I was considering is actually the # of cylinders in a same displacement range. Regarding Diesels, I know of some 3-cyl ones in a 2.9 to 3.3L range which are available in my country and can be fitted into a Ranger or any other compact truck.