Nitro radio controlled cars have a real working combustion engine that is powered by model glow fuel that contains a blend of nitro methanol and oil. This fuel is available from almost all online and high street model shops. Although small these engines are extremely powerful making the nitro cars very fast. The engine noises also add to the realism and excitement of nitro RC car racing. The different models are generally classified by scale size compared to a real car with 1:18 scale being the smallest and usually cheapest to 1:8 scale being the biggest and most expensive.
Petrol radio controlled cars are much bigger than the nitro ones, usually 1:5 or 1:4 scale. This is because the engines run on a mix of normal unleaded petrol and 2-stroke oil and are therefore much bigger so the cars must be bigger to hold them. The bigger size makes them more expensive but being able to buy the fuel from and petrol station makes them more convenient and a little cheaper to run.