When hybrid, whether full or plug-in, the new Toyota RAV4 must maintain the already known engine 2.5 Atkinson cycle aspirated with four cylinders in line and 16 valves. The expectation, however, is that the set will have significant gains in terms of power and efficiency, in addition to using lithium-ion batteries with greater capacity and density than the current 1.6 kWh (HEV) and 18.1 kWh (PHEV).