CNG offers even lower CO 2 emissions than LPG, typically on a par with diesels. This is coupled with low CO, HC and Particle emissions. The durability of the emissions performance of LPG and CNG vehicles will depend upon the quality of the conversion. New LPG and CNG fuelled vehicles are required to meet the same emissions limits at type approval as petrol engines. As emissions limits for petrol and diesel engined vehicles become tighter the gap in emissions performance between LPG and conventional fuels is narrowing.
Hybrid vehicles combine an internal combustion engine with an electric motor and battery.
There are various ways in which hybrid vehicles can operate, for example the electric motor can be used to provide additional power during acceleration and high load conditions. The battery can then be recharged by the internal combustion engine or from energy absorbed during braking. Hybrid vehicles offer reduced fuel consumption and CO 2 with potentially lower emissions of all pollutants. The Government supports the purchase of alternatively fuelled vehicles through the Powershift programme. Powershift provides information on all aspects of clean fuel vehicles and can provide grants to help offset the extra costs of purchasing an alternative fuel vehicle or converting an existing vehicle to run on an alternative fuel.