The Smart Fortwo with a gasoline engine has a speed governor that limits it to 84 miles per hour, according to howstuffworks.com. The top speed a Smart car attains also depends on the year and model.
Nonstandard versions of the gasoline Smart such as the BRABUS Forfour have a higher maximum speed, says gizmag.com. Car and Driver magazine tested the electric drive version 2013 Smart Fortwo and determined that its top speed was 78 mph. This is an improvement over the previous year's 63 mph maximum. The standard Smart cars are designed for city driving and gas savings rather than speed.