Steam at high pressure exhausting into the atmosphere is still commonly used, but the great power required for raising heavy loads from deep pits at high speeds has brought the question of fuel economy into prominence, and more economical types of the two-cylinder tandem compound class with high initial steam pressure, superheating and condensing, have come in to some extent where the amount of work to be done is sufficient to justify their high initial cost.
Honda's 140PS 2.2-litre i-CTDi diesel continues; but as aerodynamic efficiency is improved by 12 per cent, fuel economy should improve.
The catalyst engine uses high compression ratio pistons designed specifically for the 4.2 power unit to optimize fuel economy.
The fossil fuel economy is becoming ever more precarious.
Hybrid cars can reduce smog up to 90% and can get much better fuel economy then a normal engine.
