Motoring Advice

The type of engine you choose will greatly affect the character and performance of your vehicle. Alternative fuels such as gas and electricity are just starting to catch the public imagination - especially in London where they are not subject to the Congestion Charge.

At present, the main choice is still between diesel and petrol, with diesel driving just over a quarter of all new cars sold today. Diesel sales have soared in the last three years for two reasons. Firstly, the Government made changes to the taxation of company cars which benefit cars with low carbon dioxide (CO2) emissions. Diesels always score well for CO2, although most diesels have to pay a small excess due to their higher emissions of other pollutants (mostly small particulates). Secondly, there has been a revolution in diesel technology. In recent years, "common rail" diesels have been developed which are far more powerful (and more economical) than older designs. Common rail works by injecting all the fuel from a single pipe, or rail at immense pressures - over 10,000 pounds per square inch, the idea being that the higher the pressure, the greater the engine's efficiency. If you are considering a diesel, make sure that it is common rail - typical abbreviations are CDI, CRD etc.

The latest diesels are always more economical than the equivalent petrol (typically 30% better), but they may be more expensive to buy and diesel is no cheaper than petrol. More surprisingly, diesels are now often nicer to drive than petrols - they have more power between 30 mph and 70 mph, which is where you need it most. They are also quieter on the motorway as they are lower revving (i.e. the engine is running more slowly for a given road speed). However, diesels are still noisier when they are cold, so a 6 a.m. start in winter can have you worrying about waking the neighbours.