Trucks use diesel engines which are 20% to 25% more fuel efficient than petrol engines. Technological advances are giving trucks even greater fuel efficiency. Current engines use 50% to 60% less fuel than 15 years ago. A heavy truck today uses one third less fuel compared to 20 years ago.

As well as requiring a lot less fuel to move a tonne of freight, today’s technology has produced a dramatic drop in greenhouse gas emissions from trucks. And even cleaner burning engines are on the way. As well as improved diesel engine technology to meet more stringent emissions standards, manufacturers in Europe and the United States are developing diesel-electric engines which they claim can reduce urban fuel consumption by up to 35%.

Moving to large trucks carrying heavier loads has improved fuel efficiency per tonne-kilometre. It has also reduced the number of trucks needed for a given freight task, further cutting fuel use and emissions.

A 2007 study by the Heriot-Watt University Logistic Research Centre for the British Commission for Integrated Transport, found that CO2 emissions from road freight transport grew at roughly a third of the rate of road tonne-kms between 1990 and 2005. The Centre concluded that the declining CO2 intensity per tonne-km for HGVs can be mainly attributed to a reduction in empty running, net consolidation of loads and improved fuel efficiency.

Modern technology also means road transport is more fuel efficient than rail over the 100 kilometres or less most freight travels. European research in 2002 confirmed that truck transport can be more fuel efficient than a train when hauling the same load between common destinations. These conclusions have been backed up by research in New Zealand. A 2005 study for the Wellington Regional Council found that a train produces 31% more CO2 than a truck hauling a tonne of freight from Masterton to Wellington and nearly 40% more between Marton and Wellington and Wanganui and the capital.