Most modern motor scooters have smaller wheels than motorcycles, between eight and 12 inches (20-28 cm) in diameter (though maxi- and big-wheel scooters may have larger wheels). Most scooters have smaller engines than motorcycles (between 30 cc and 250 cc with a single cylinder, though larger models have twin cylinder 400 to 650 cc. motors).

Most jurisdictions have no legal definition for "scooter". Scooters increasingly have four-stroke engines to meet stricter emissions controls. Trends world-wide have seen new variations on the classic scooter. A common variation, the 'big-wheel' or commuter-style scooter features wheels as large as a motorcycle.

High-end scooter models now include comprehensive technological features including cast aluminum frames, engines with integral counter-balancing, and cross-linked brake systems.