The Toyota RZ engine family is a straight-four piston engine series built in Japan. The RZ series uses a cast-iron engine block and aluminum SOHC or DOHC cylinder heads. It has electronic fuel injection (EFI), 2 or 4 valves per cylinder and features forged steel connecting rods.

1RZ

The 1RZ is a 1998 cc version built from 1989. Bore and stroke is 86x86 mm. The original carburetted model in Japanese trim produces 100 PS at 5,400 rpm and maximum torque of 16.5 kgm at 2,400 prm. Applications:

1RZ-E

The 1RZ-E is the fuel-injected version of the 1RZ. With a compression ratio of 9.0:1 and in Japanese trim, output is 110 PS at 5,200 rpm and maximum torque of 17 kgm at 2,600 prm. With redline at 5,500 rpm. Applications:

2RZ

The 2RZ is a 2438 cc version. Bore and stroke is 95x86 mm; a variety of combination of heads and fuel delivery systems were available.

2RZ-E

This is an SOHC engine with two valves per cylinder. Valve adjustment is by shim over bucket. Output is 120 PS at 4800 rpm with 146 lb⋅ft (198N⋅m) of torque at 2600 rpm. It does not have balance shafts and is known for vibrations. Originally manufactured with a carburetor induction system, it was later upgraded to Electronic Fuel Injection, with the -E suffix added to the engine designation. Toyota specified unleaded fuel with a rating of at least 91 RON in Australia. Applications:

2RZ-FE

The 2RZ-FE, and 4RB1 or 4RB2 in China, is a 2438 cc version. Bore and stroke is 95x86 mm. Compression ratio is 9.5:1. Output is 142 hp at 5000 rpm with 160 lbft of torque at 4000 rpm. This engine does not feature balance shafts. It has four valves per cylinder and DOHC. Valve adjustment is by shim over bucket. The 2RZ-FE is an interference engine with a timing chain. A 2185 cc version called the 4RB3 is also manufactured in China which has a bore and stroke of 91 x, while sharing the 2RZ's 102.5 mm bore spacing. According to a review in 2023, there are reports of the engine typically lasting over 250,000-300,000 miles and less frequently 500,000 miles. Applications:

3RZ

3RZ-FE

The 3RZ-FE is a 2693 cc version. Bore and stroke is 95x95 mm. Compression ratio is 9.5:1. Output is 150 hp at 4800 rpm with 177 lbft of torque at 4000 rpm. This engine features twin, chain-driven balance shafts. It has four valves per cylinder and DOHC. Valve adjustment is by shim over bucket. The 3RZ-FE is an interference engine with a timing chain reported to last 150,000 miles. The cylinder head is composed of aluminum alloy and the intake manifold is made from aluminum. Applications: