The first Daf LF hybrid truck has rolled off the production line in Leyland, Lancashire.
It is a 12 tonne GVW chassis cab and has a 44 kW motor/generator sandwiched between the clutch and the gearbox, which the firm says can improve fuel economy by up to 25 per cent and drive the truck for up to 2 km on battery power alone. Pulling away from a standstill is usually done using the electric motor’s 400 Nm of torque (reducing clutch wear) while the engine becomes the prime mover once the power demand exceeds 44 kW. The combination of both engine and motor provides 700 Nm of torque between 650 rpm and 1,950 rpm.
When the driver takes their foot off the accelerator, the electric motor switches into generator mode to recharge the 96 batteries (each 3.6 V) and acts as a vehicle retarder. The amount of electrical retardation is increased during the initial application of the foot brake, saving wear on the foundation brakes which only come into play when a higher degree of retardation is required.
As the technology is untried, Daf is initially only leasing these vehicles and product manager Phil Moon admits that even with fuel prices hitting new heights, the system will not repay the around £800 month needed to cover the additional leasing costs. He says: “This is primarily an urban vehicle so it won’t cover enough miles to pay back the additional cost through fuel savings alone. Companies expressing an interest are those with a big environmental commitment or that wish to demonstrate to their green credentials to their clients and customers.”
In the construction sector he identifies councils and utility companies, along with their subcontractors, as possible users as well as developers considering projects in city centres where particulates pollution from diesel engines can be a problem. Mr Moon says the technology could also be attractive for urban skip hire companies and builders merchants doing stop/start and multi-drop operations and the company is evaluating operating loader cranes and tail lifts from the drive batteries.
Sales of such hybrids are at their highest in countries offering financial incentives or in cities where diesel engine vehicles face operating restrictions. Currently this type of hybrid doesn’t qualify for a Congestion Charge discount despite Daf, and other manufacturers, continued lobbying of the Greater London Authority.