|Number of wheels ||2 (sometimes with training wheels)
||Four, usually, however smaller cars may rarely have three wheels, as with the BMW Isetta and Reliant Robin.
|Number of seats ||from 1 to 3
||some have just two, some have three, some four. the majority have five. vans etc have sometimes 12. people carriers normally have 8 or 9.
|Pollution ||Almost none. Only needs a bit of oil and rubber (tires, etc.)
||greenhouse effect gases emissions. They are evil, dirty, smelly and noisy and will kill you.
|Maximum speed ||35-40 mph (on "normal" bikes. World record: 133.78 km/h (83.13 mph) Flat surface, unpaced)
|Safety ||Helmet, gloves and closed shoes are essential.
||Numerous safety features, high speed impacts during crash, may still prove fatal
|propulsion ||Human legs muscle powered.
||petrol : either unleaded or diesel
|Uses ||Very versatile, can be used for commuting, fun, exercise, racing, load, etc.
||Killing the environment, killing people, making roadkill
|Pros ||Your food is your fuel. Almost no pollution. Very quiet (almost zero noise). Extremely high cost/benefit. Cheap. Easy and low maintenance. Gives you better fit and health. You can ride more freely than any other vehicle.
||They are quick to refuel
|Cons ||Traffic and weather can be an issue, specially WIND. You get tired, but that depends on many factors. Fragility. You may get hurt in a fall, but hardly die.
||They are horrible for everything. They are too noisy, belch dirty black smoke, and make roadkill. They are evil and noisy and dirty.
|horsepower ||Up to 2hp (peak of pro cyclists).