How far can you go with 1 liter of diesel van?

about4.2km

Updated answer,

4.2km, and how far can you go with a carbon fiber tank full of compressed air, this is what MDI has been trying to find the answer to, and to a point they have found the answer. Clean cars google MDI compressed air cars, and see what they are trying to achieve.

A car to clean the air of cities, yes it may be inefficient, but would you drive an inefficient car if it did not pollute the air you breath.

Petrol cars were inefficient when they were first developed, have a look "Get Behind the Compressed air car and maybe you'll breath"