The speed of the go-kart will vary. Pedal go-karts are reliant on pedal power, so the child will need to pedal faster to go faster. On the other hand, electric and petrol go-karts have engines that provide power, so the speed is limited by how fast the engine can go. Most electric go-karts have a maximum speed of around 12mph, while petrol go-karts can reach speeds of up to 30mph.