 They must be able to brake from 60 to 0 mph in less than , meet existing noise standards and use tires that meet automotive or motorcycle (alternative class only and only if the vehicle is otherwise eligible to be classified as a motorcycle) standards.Both must meet the same set of static and dynamic stability requirements.The mainstream vehicle must seat at least four adults with at least two side-by-side front seats, have at least of useful cargo space in one contiguous location not counting the passenger seats, accelerate from 0 to in 15 seconds or less, and be able to drive without refueling or recharging.