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CONCLUSIONS
Page 67
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• In service, the gas-powered ERF has used around 20% more gas than it would diesel. This is as a result of the engine's design (see engine technology). In the urban environment in which it usually operates, the engine is operating on part-throttle, its least efficient operating cycle.
On our test route, we tended to work the engine much harder over the Derbyshire Peaks and motorway sections. With the throttle wide open, its efficiency improves dramatically, which is why it performed so well on the tougher sections. Overall it was only 5.7% less efficient than the diesel.
Around the Loughborough/Loughborough loop, the gap widened to 9.4%, reflecting the greater mix of urban driving on this section and more part-throttle running. A greater proportion of urban running would push the gap toward the BOC 20% operational difference.
At the time of our test, the pump price of gas was 70.5p per kg (the unit in which it is sold at the pumps) and diesel was around 60p/lit. Tax accounts for 28.17p per kg of the gas price-the highest level of tax on gas as a fuel levied in the EU. This was nearly three times the tax levied in Germany, which imposes the next highest level of tax in the EU.
In the Budget, the Government reduced the tax level on gas by 25% taking the pump price to 62.3p per kg. At the same time duty on diesel rose by 5%, around 3p per litre.
Using these figures, the diesel truck used £181.50 worth of fuel on the test compared with £175.83 worth of gas in the gas truck. After the Budget, the figures change to £190.58 for the diesel and £155.38 for the gas. Bunker prices would be lower in both cases.
If we use BOC's operational experience of 20% higher fuel consumption than the diesel, the situation changes. At post-Budget prices, the gas truck would have used £176.40 worth of fuel in that case.
The Chancellor made it clear in his speech that it is urban air quality he wants to see improved most urgently.
As we have already seen, this is where gas engines perform least effectively and 20% higher consumption than diesel under these conditions is currently realistic.
Before we get carried away, it is necessary to consider the whole picture. On the plus side, the chancellor's £500 annual concession on VED should apply to gas-powered vehicles when it is introduced in 1998.
Besides the cost of gas, there is the cost of buying the vehicle and the effect on resale values. There is an additional cost for buying a gas engine, because they are produced in relatively small quantities. It is hard to put a figure on it but it will be in the thousands, although it should reduce as production engines come on stream. Resale values are bound to be lower too, again because there are so few on the road, but that situation will also improve as more are made available. Then there's the matter of infrastructure. Right now you can refuel a diesel truck just about anywhere in the UK. Not so with CNG.
Although the Budget has helped to reduce the price of gas as a fuel, it is not a great enough incentive to hauliers thinking of running a gas-powered vehicle.
As Sam de Beaux told us: "To open the gates to gas, duty needs to be around lip per kg. In real terms, the Budget makes no difference to natural gas vehicles on the road today.
"At present it is not commercially viable but it may be worth staying with it, particularly if it is possible to get some of the grant funding available."
His views were endorsed by Kevin Prendergast of the Lane Group, which runs a gas-powered ERF for the Body Shop.
Technology doesn't stand still and future gas engines will be more efficient. While we don't think that hauliers will be queueing to buy gas-powered trucks yet, the situation is slowly changing. Tax is still too high on natural gas and if the Government continues to reduce it in the future, it could encourage more hauliers to try it out.
• Our thanks to BOC, British Gas. ERF and Perkins for their help and support.