Automobile engines require four strokes to complete a cycle and are much heavier because they require extra systems and components, which make them cleaner and more efficient. Description from washingtonpost.com. I searched for this on bing.com/images
Powered by the 250cc liquid cooled, four stroke engine, the 505 pound machine comes with added features to reduce fuel consumption even when running at a decent speed of 65mph. The designer states that the fuel efficiency drops to 105mph when some bling is added to the vehicle in the form of sporty steering, bling wheels and a couple of other mods to improve the looks of the trike.