The engine series features many advanced technologies including slant-squish combustion chambers, offset cylinder and crank centers, and the VVT-i continuously variable intake valve timing system.

The forged steel crankshaft is fully balanced with eight counterweights and supported by five main bearings.

The dual overhead camshafts are driven by a single-stage roller chain of 8 mm (0.31 in) pitch, enabling a narrow included valve angle of 27.5°.

As in the smaller NZ engine, the new AZ adopts a plastic, built-up, and vibration-welded intake manifold integrating a large volume plenum chamber (3.5 L (210 cu in) volume including a 1.3 L (79 cu in) resonator).

[2] If this Toyota engine is burning more than 1 US quart (946 ml) of oil in 1,200 miles (1,931 km), has less than 150,000 miles (241,402 km), is less than 10 years old, and is located in the U.S., Toyota service will perform a free oil consumption test to determine if the engine is affected.

The 2AZ-FE is a 2.4 L (2,362 cc) version built in Japan (Kamigo Plant and by Toyota Industries Corporation), at TMMK in the USA and also built in China for select Scion xB models, and also in Australia, obtains a total displacement of 2.4 L (2,362 cc) with 88.5 mm × 96 mm (3.48 in × 3.78 in) bore and stroke, with a compression ratio of 9.6:1.

Later versions of the 2AZ-FE engine were upgraded with 9.8:1 compression ratio, a slightly more aggressive intake cam profile, 6500 rpm redline, and piston oil squirters.

Some Japan-made Toyota vehicles with the 2AZ-FE engine were equipped with the K112 transmission also referred to as 7-speed Super CVT-i automatic (Seven-speed Sequential Shiftmatic) from October 2005.

[citation needed] A TRD supercharger was available for the Scion tC and 2nd generation xB until Spring 2009.

Alternative theories point to a head gasket problem: the 2AZ-FE aluminum block threads may wear out on the back three middle bolts (closest to firewall).

The longer than normal open intake valve duration leads to a reduction in cylinder charge and reduced torque and power output, but efficiency is increased.

This combination makes the 2AZ-FXE suitable for use only in hybrid vehicles, where peak torque and power demands can be met by the electric motor and battery.