The 2AZ-FE engine is a 2.4-liter inline-four gasoline engine developed by Toyota as part of its AZ engine family. Introduced in the early 2000s, it became a staple powerplant in a range of Toyota and Lexus vehicles, including models like the Toyota Camry, RAV4, Highlander, and Scion tC. The engine features an aluminum alloy block and aluminum DOHC (Double Overhead Camshaft) cylinder head, which contribute to its relatively light weight. It utilizes sequential multi-port fuel injection and VVT-i (Variable Valve Timing with intelligence) on the intake camshaft, which improves fuel efficiency, torque, and emissions control. With a bore and stroke of 89.0 mm × 96.0 mm, the engine has an undersquare design, favoring torque production in the lower to mid-RPM range. Its compression ratio is generally 9.6:1, although variations exist depending on the vehicle and market specifications.

The 2AZ-FE is known for delivering a balance between performance and efficiency, typically producing around 160–170 horsepower and 165–170 lb-ft of torque, depending on the application. It uses a timing chain instead of a belt, reducing long-term maintenance needs. However, the engine is not without its flaws—early production versions (especially pre-2007) were plagued by issues such as excessive oil consumption due to poor piston ring design, prompting class-action lawsuits and extended warranties in some regions. Later revisions improved durability and reduced oil consumption. The engine also includes features like a balance shaft system to reduce NVH (noise, vibration, and harshness), contributing to a smoother driving experience. Overall, the 2AZ-FE remains a widely used and easily serviceable engine with a reputation for reliability, particularly in its post-revision versions.