About the only things that remain the same with the engine is that it is a flat-6 that displaces 1,833cc. The redesign focused on lighter weight, smaller size, and improved fuel economy. Bore was reduced by 1mm, and stroke has been increased by 2mm for square 73.0 x 73.0mm cylinder dimensions. New high-strength steel alloy allows for a thinner crank webs and less distance between each cylinder, which combines with other internal upgrades resulting in an engine that is now 29mm shorter end to end. Even with the switch from two-valve to four-valve, which increases efficiency but adds weight, the manual-transmission engine is 13.7 pounds lighter, and the DCT unit is 8.4 pounds lighter than previous manual models. A Unicam valve train like the one used in Honda's CRF450R enables the removal of the valve-lifter support structure, resulting in lighter weight and a more compact design. Couple the more efficient engine with overall weight reduction and an 11.8 percent more aerodynamic design, and Honda says this results in a 20 percent increase in fuel economy. So, even with fuel capacity reduced by 1.1 gallons to 5.5 gallons, Honda states we won't see any decrease in range per tank. With the engine further forward, the engineers were also able to move both the rider and passenger farther forward, keeping weight as close to the bike's center of gravity as possible.