2025 Lexus RX 350h

Dynamic Force

2.5L I4 Hybrid

A smooth, efficiency-first Atkinson-cycle four paired with electric assist, prioritizing quiet, seamless low-rpm response and frugality over outright drama. Power delivery is calm and refined, the hallmark of Lexus hybrids.

This is Toyota's A25A-FXS from the Dynamic Force engine family, introduced in 2017 and shared across the Toyota/Lexus hybrid lineup; it's the hybrid sibling of the standard A25A four-cylinder.

• It runs an unusually high 14:1 compression ratio and achieves roughly 41% thermal efficiency, among the best of any production gasoline engine.
• The same core engine powers a huge swath of Toyota and Lexus hybrids, from the Camry and RAV4 to the Lexus NX and RX.
• It uses an Atkinson-cycle valve strategy with delayed intake valve closing to trade some power for efficiency.