The Hardstaff Group has developed a dual-fuel – diesel and natural gas – system in conjunction with Mercedes-Benz.
The Nottinghamshire-based haulier has taken a fleet of 31 Mercedes-Benz tractor units, which are now available to all, sold and supported by the Mercedes-Benz dealer network in the UK.
The patented oil ignition gas injection system works with the existing diesel drive train. It automatically reduces the amount of diesel injected into the engine, replacing it with the same energy equivalent of natural gas.
The injection equipment is able to vary the amount of gas metered into the engine – known as the substitution rate – depending on operating conditions and engine load. Starting from cold, and moving off, power is supplied by 100 per cent diesel but as the vehicle reaches cruising speed, substitution rates of up to 70 per cent are commonly achieved.
The substitution has no effect on the vehicle’s performance, from the driver’s seat a small dashboard light is the only sign that gas injection is underway.
Steve Storrar, Hardstaff’s vehicle applications manager, said: “The advantages of the system are both environmental and economical. If you reduce the amount of diesel being burned, and replace it with methane, you get a significant reduction in regulated exhaust emissions, while gas is about half the price of diesel in most countries.”
Conversion includes the fitting of gas injection hardware, an additional electronic control unit, filling equipment and tanks to hold the compressed or liquefied natural gas fuel, takes place in Hardstaff’s workshops at its Kingston-on-Soar site, and the process typically takes three days.
Various options are available, depending on the vehicle type and application – on long-haul articulated units, for example, gas tanks can be fitted to both tractor and trailer to maximise storage capacity and range.