The most fuel-efficient 40 ton truck is the Mercedes Benz Actros, which uses 19,44 litres per 100 km (6.88 gal per 100 miles) under test drive conditions. It was tested at the High Speed Track of Nardò, Brindisi, Italy, on 29 May 2008
This average was established by driving the truck for one week 24 hours a day over 12,728 km on the test track. The whole test was monitored at all times by DEKRA, an independent testing firm for trucks.
Comments below may relate to previous holders of this record.