Exhaust gas
Exhaust gas emission from an internal combustion engine is significantly lower on wood gas than on petrol. Especially the hydrocarbon emissions are low on wood gas. A normal catalytic converter works well with wood gas, but even without it, emission levels less than 20 ppm HC and 0.2% CO can be easily achieved by most automobile engines. Combustion of wood gas generates no particulates, and the gas renders thus very little carbon black amongst motor oil.