One sentence in the traffic law puts petrol 50s and electric mopeds in the same box: both are xe gắn máy — no licence, minimum age 16, helmet compulsory. From the second sentence onward, they are different machines, and the choice between them is about how you ride, not how the law sees you.

The shared rule

Article 34(1)(g) of Law 36/2024/QH15 defines the moped category as vehicles designed for no more than 50 km/h with engines of 50cc or less, or electric motors of 4 kW or less. Everything legal flows identically from there: same age floor, same helmet duty at the same fine levels, same traffic rules, same compulsory-insurance framework. The licence article carries the details; the electric licence article covers where the moped line sits in the electric spectrum (pedal e-bikes below, licence-class electrics above).

Refuel versus recharge

A petrol 50 refuels in a minute at any of the city’s stations, and a jerry can at home extends that indefinitely. An electric moped recharges over hours from a household socket — fine overnight, restrictive mid-journey. For predictable daily loops with a home plug, the electric never feels the constraint; for improvised long days, the petrol 50 wins without contest.

The way they deliver power

Electric motors deliver their push from zero rpm — brisk, silent launches that surprise riders and pedestrians alike. Petrol 50s build revs into their urge and announce themselves doing it. Neither is “faster” in a way that matters at moped speeds; they differ in character — and in the electric’s case, in the obligation to ride the silence responsibly: pedestrians do not hear you coming, so lights and defensive habits carry more of the load.

Upkeep

  • Petrol 50: the classic small-engine routine — oil, chain, brakes, carburettor or injection, filters — covered across our maintenance articles.
  • Electric moped: batteries, controllers and connectors instead — our electric maintenance article covers the care pattern; the big cost event is eventual battery replacement.

Costs and range honesty

We publish no fixed figures for either class: petrol consumption depends on condition and right hand; electric range depends on battery age, load, speed and terrain, and any claimed range should be treated as a manufacturer’s test-condition number, with real-world range lower. Compare real bikes, ask owners, and judge each machine on its condition — our running-costs article covers the petrol side of the ledger.

Choosing

Predictable flat commutes with home charging and a taste for silence: the electric moped. Longer loops, spontaneous trips, and a fuel network instead of a socket: the petrol 50. The law will not help you decide — for once, it genuinely does not mind.

The 4 kW boundary in practice and the reason sub-50 km/h versions exist are covered in electric-moped-vs-electric-motorcycle-vietnam and why-electric-mopeds-capped-50kmh-vietnam.