Keep in mind the original XL1 vw 1liter prototype was a diesel and got 317mpg(unconfirmed). I don't know the tested mph however.
At small displacements, there maybe some advantages to a diesel in the area of thermal efficiency. But I won't expect that to be more than 10-15%.
The original XL1 and vehicles my university entered into competitions were very light weight, small frontal area, and good coefficient of drag. Pretty much standard engines de-tuned for the street and of course the right gearing. That's pretty much Elio tech right there.
At small displacements, there maybe some advantages to a diesel in the area of thermal efficiency. But I won't expect that to be more than 10-15%.
The original XL1 and vehicles my university entered into competitions were very light weight, small frontal area, and good coefficient of drag. Pretty much standard engines de-tuned for the street and of course the right gearing. That's pretty much Elio tech right there.