The first Acty trucks were introduced July 27, 1977, and replaced several "Keitoras" Honda had previously offered, such as the Honda TN360 (most recently sold as the TN7) and the Honda T360. On 1 September 1975, the Japanese Government revised the rules on Road Trucking Vehicle Law that regulated the dimensions and engine size of vehicles in this class. As a result, the first Acty trucks and vans were available with a "midship" mounted 545 cc 2-cylinder SOHC water-cooled engine, known as the EH engine, which produces at 5500 rpm and of torque at 4000 rpm. This was about 50% larger than the engine used in the preceding TN7. Export models, with less emissions equipment, claim at the same engine speed.