Environmental pressures plus the need to reduce the UK's dependence on oil from unstable areas of the globe mean that more and more vans will be running on biodiesel — or at least a blend of biodiesel and conventional diesel — over the next few years.

Supermarket giant Tesco is already selling diesel with a five per cent biodiesel content from selected forecourts in the South East of England and Scotland; the strongest blend widely available to retail buyers in the UK. It sources its biodiesel from Greenergy, which it partly owns.

Biodiesel 

So what is biodiesel? It's diesel made from renewable sources such as rapeseed oil, soya and even waste animal fat — commonly known as tallow — and used cooking oil

While the planet's reserves of mineral oil are finite, the crops used to produce biodiesel can be grown again and again; and there's no indication that the world is about to run out of tallow or time-served cooking oil.

In a bid to encourage biodiesel's use, the government has introduced the Renewable Transport Fuel Obligations regulations. They mandate that at least 5 per cent of all fuel sold on UK forecourts must come from a renewable source by 2010.

Tax Efficient

It also treats biodiesel more kindly than standard diesel from the tax viewpoint. At just 28.35p a litre, the duty on the former is significantly lower than the 48.35p levied on the latter.

It's being careful, however, not to be too over-generous. When fuel duty rates were increased by 1.25p a litre last September by Chancellor of the Exchequer, Gordon Brown, the rise was applied to biodiesel as well as to other road fuels; a step that roused the ire of the Green lobby.

So what are the advantages of running on biodiesel? For a kick-off it helps rein in emissions of greenhouse gases. At worst it is carbon dioxide (CO2) neutral, while at best it can lead to substantial CO2 savings.

Tesco reckons that its decision to run three-quarters of its 2,000 trucks on a specially sourced 50 per cent biodiesel/50 per cent straight diesel blend that it keeps in the bulk tanks used by its fleet will help cut its output of CO2 and other greenhouse gases by over 70,000 tonne annually.

Biodiesel generates fewer soot particles and less carbon monoxide than standard diesel, has twice the flashpoint — good news from a health and safety viewpoint — and is less carcinogenic.

The tax break it enjoys also means than it's cheaper than ordinary diesel, but the fact that producers don't usually enjoy the similar economies of scale as the giant refineries turning out mineral diesel means that the price differential is more likely to be 2p to 3p rather than 20p. That's unlikely to be reflected overmuch in the five per cent blend sold from certain forecourts.

Drawbacks?

Some vehicle makers have expressed concern about emissions of oxides of nitrogen (NOx) and warn that the lower calorific value of biodiesel when compared with ordinary diesel means that engine performance may fall off and fuel consumption may rise. They add that the fuel may also become waxy in cold weather.

    
None of these issues are likely to affect users of a five per cent blend, however, and engines are unlikely to come to grief if the blend is sourced from a reputable outlet. Citroën is happy for a 30 per cent blend to be used in the 1.6-litre HDi common rail diesel fitted to Berlingo, while in France Renault has unveiled common rail diesel Trafics and Masters that will run on the same mixture.

Certain manufacturers, however, aren't keen on fuel with a biodiesel content higher than five per cent being used in their engines. Worried that it will clog filters and rot engine seals, they insist on shorter drain intervals and engine modifications that typically involve special hoses and seals and a water separator being fitted.

A separator is needed, they argue, because biodiesel is hydroscopic. In other words, it attracts water; and the last thing you want is water in your fuel.

Some engineers also fear that lubricity problems associated with strong concentrations of biodiesel could affect the high pressure pump used in a common rail fuel injection system; problems Citroën and Renault appear to have overcome, at least so far as a 30 per cent blend is concerned.

While they may differ on the concentrations of biodiesel they are willing to tolerate, all van makers agree that any biodiesel used in their vehicles must comply with standard EN14214. If it is blended, then the fuel it is mixed with must meet EN590; the standard that conventional diesel has to achieve.

Oil Changes

The more frequent oil changes that may be required if a van runs on biodiesel may be welcomed by dealers as a source of extra business, but not by environmentalists. Aside from the health hazards it presents, waste oil is a potential source of pollution and has to be disposed of responsibly, not tipped down the nearest drain; something that van owners still changing their own oil should always bear in mind.

Normal Service

Not that all dealers are capable of coping with the work they've already got, or of meeting the particular requirements of goods vehicle operators. There is, for example, precious little point in handing a van owner a small hatchback as a courtesy vehicle when he brings his pride and joy in for a service when what he has brought in happens to be a dropside 3.5-tonner.

There are signs that manufacturers are starting to appreciate the shortcomings of their networks, however, and are doing something to remedy them.

In doing so they are often looking to heavy truck dealers — obliged to provide round-the-clock back-up by their demanding haulier customers — for inspiration. Fiat for instance has appointed a number of Iveco distributors as van dealers along with Adams Morey, a prominent south coast Daf distributor.

In their turn, heavy truck dealers are becoming more oriented towards light commercials. Now selling the Maxity 3.5-tonner as well as the Master, Renault Trucks will soon be rolling out a van aftermarket support programme through its dealer network that will ensure that certain jobs — oil changes, brake repairs, replacing dampers and so on — are carried out in less than two hours.

Workshops will install purpose-built van bays if they don't already have them, will offer maintenance contracts and be geared up to tackle major, time-consuming jobs such as engine, gearbox and clutch replacement. Service customers will be able to obtain courtesy vehicles to tide them over while the work is being done; and they won't be offered a family runabout if they need something to take to a building site.

Franchised dealers either unable or unwilling to get their act together should be aware that they face competition from operations they wouldn't have encountered a few years back.

Contact Prestige Van Servicing, for instance, and it will collect your vehicle free of charge either from home or from work, service it, and deliver it back to you. With upwards of 400 branches nationwide it reckons to offer savings of up to 33 per cent on the prices charged by dealers and stresses that the work it does will not invalidate the vehicle's warranty.

This last point is an important one. No matter what a dealer may seek to imply — and the sensible ones don't these days — your warranty will not be affected if your van is serviced by a non-franchised outlet so long as it is working to the same standard as a franchised dealer. Many do; and we can think of one or two that exceed it.

VERDICT

If an operator has access to biodiesel it makes sense to use it, but always check with the vehicle manufacturer first and get it in writing that it's all right to use. The last thing any one needs is a warranty problem to arise at some later date.

Misleading Figures

Going back to CO2 for a moment, figures for the emissions saved and the benefit to the planet can sometimes be misleading. They don't always include emissions from the agricultural vehicles used to harvest crops to be used as feedstocks for biodiesel for instance.

A further concern is that some biodiesel is made from palm oil and soya sourced from Third World countries. The worry here is that the land used to produce both may have until fairly recently been occupied by rain forests that have been cut down so that a cash crop can be grown, negating any environmental benefit.