diesel (assuming same displacement) - low engine top speed, high torque, lower horsepower output. result is low vehicle top speed but very good low speed (and thus offroad) performance.

gas (assuming same displacement) - high engine top speed, low torque, higher horsepower output. result is higher vehicle top speed but since engine torque is lower, low speed control is not as good as a diesel.

lower ang fuel consumption ng diesel on a km/liter basis for the same engine displacement.

but since diesel engines have generally lower horsepower ratings than gasoline engines this comparison for same engine displacement is not valid. what you should ask is the fuel consumption of a gasoline engine and a diesel engine with the same horsepower rating.