Fuel-Efficient Vehicles

A diesel car typically gets 30% greater fuel economy than the same car with an equivalent-horsepower gasoline engine. On the downside, more petroleum is required to produce a gallon of diesel than a gallon of gasoline. Diesel engines also have worse particulate (soot) emission than do gasoline engines, although modern diesels have improved in this regard.
In Europe, high fuel costs have made diesel cars the standard.

Choosing manual transmission over automatic transmission can gain you 1-3 miles per gallon of fuel.

Gasoline-powered scooters, such as those made by Vespa, Honda and Kymco, typically get 60 to 90 miles to the gallon.
Although these vehicles usually only carry 1 person, they enjoy the benefits of easy parking and the ability to "slip through" traffic congestion.
Equipped with a trunk or baskets, scooters become practical for commuting and errands.