When choosing which type of engine you should choose for towing your touring caravan or trailer or when buying a motor home there are a number of factors that you need to take into account. Your choice of a vehicle will depend upon the use to which it is put. Someone requiring a vehicle for day to day use together with use at weekends and holidays with camping gear in the back may only be interested in performance or fuel efficiency or the best compromise of the two.

Someone considering towing a touring caravan will not only be looking for economy and performance but also for other factors like brake horsepower and torque. At present there are two main fuels petrol and diesel. But other fuels like gas are beginning to enter the market. In this Data Sheet we explore the differences between the two major fuels petrol and diesel and take a look at what other fuels will be available in the long term and whether they will be any good for vehicles used for towing.

What makes a good tow car and which is best petrol or diesel? These are questions that we are often asked. Besides making sure you have the right weight ratio between car and trailer and the correct gear ratios, there are other factors that should be taken into consideration. Brake horsepower (BHP) is the amount of power produced by the engine. Torque provides the pulling power. Different engines produce variable amounts of BHP and torque dependent upon speed and the type of fuel used. For towing you need a large amount of power and maximum torque early and over a wide range of the engines variable speed. Petrol and diesels give similar amounts of power and torque but at different times during the engines revolution band.
Petrol engines
■ Tend to produce more BHP than diesels.
■ Acceleration from a standing start is quicker.
■ Cleaner than older diesels.
■ Petrol and diesel is around the same price in the UK but petrol is dearer on the continent.
■ Petrol engines are generally lighter.
Diesel engines
■ Can be more expensive to buy.
■ Can be noisier than petrol.
■ Produce maximum torque at lower engine speeds.
■ Give more miles to the gallon than petrol.
■ Emissions from older engines may be dirtier than their petrol equivalents.
■ Older vehicles may require more frequent servicing.
■ Retain torque over a wider engine revolution range.
Other fuels
With the drive towards lower exhaust emissions, increases in fuel prices and government environmental policies, there is a growing interest in other types of fuels being used as alternatives or additions to petrol and diesel.
Gas engines
Gas engines have been around for a long time. Australia, Holland, Italy, Japan and North America have many thousands of cars powered by gas. Only recently are they becoming more popular in this country.
Gas is cheaper than both petrol and diesel, produces a lower power output but has a cleaner exhaust. A major drawback is that a gas tank is bulkier and heavier than a petrol or diesel tank and often uses boot space.
There are two main types of gas Compressed Natural Gas (CNG) and Liquid Petroleum Gas (LPG). There are not many CNG filling stations around but there are an increasing number available at petrol stations.
British Gas is hoping to introduce a domestic CNG vehicle filling system. Drivers will be able to fill up their tank overnight from their household gas supply. If you intend using gas as a fuel, always employ a recognised converter. Contact the LP Gas Association for your nearest one. Car manufacturers are already offering converted vehicles. Volvo has a CNG option, Ford has five alternative LPG vehicles and Vauxhall has a dual-fuelled range including Astras, Vectras, Omegas and the Zafira.
Future fuels
■ Biodiesels are derived from oil-rich crops such as rapeseed, sunflower, palm, olive and Soya beans. These can be used with little or no modification to a normal diesel engine. Cost of production is the main barrier.
■ Dimethyl ether is derived from natural gas or methane and can be used in diesel engines. It is used mainly in the Scandinavian countries due to its lower emissions.
■ Batteries offer an environmental friendly alternative power source but have restricted output. At present batteries are impractical for travelling large distances and require a number connected together with the consequential weight disadvantage.
■ Hybrid vehicles, which combine petrol or diesel engines with an electric motor, are under development. They will play a vital role in cutting emissions.
■ Cars are being developed that utilise fuel cells that combine hydrogen and oxygen to produce electricity.
These type of engines will not be available for several years and will need a new fuelling network.

These tips were brought to you by Club Care Caravan Insurance