The first thing you have to look at is the refining process. Gasoline is a distilate and diesel is a light oil and not as highly refined. Although both are processed from crude it takes more energy to refine and produce a gallon of gasoline than a gallon of diesel. Your net yield in energy is lower on a gallon of gasoline right from the beginning. Then compare the same volume of fuels when they are combusted in vehicles and the diesel releases more energy and is more efficient on each combustion stroke from idle to high rpm.
A winner no matter how you look at it...... high yield, high efficiency, high energy & low emmissions with a little scrubbing!
Cheers
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FRED
Daily Driver: 98 E300TD 199K
Hobby Car: 69 Austin Mini
Past Diesels: 84 300SD, 312K
87 300SDL, 251K
94 Chev. K-1500 6.5Ltr.TD, 373K