The Toyota SZ engine family is a series of straight-4 piston engines with a forward-facing exhaust. Toyota Motor Manufacturing (UK) in Deeside produces SZ engines for the Yaris. All three types of the SZ engine are built in Tianjin FAW Toyota Engine Co., Ltd. (TFTE) Plant No. 1 in Xiqing District, Tianjin, China. The 2SZ-FE and 3SZ-FE variations are also manufactured by PT Astra Daihatsu Motor's Karawang Engine Plant in Indonesia.

1SZ-FE

The 1SZ-FE was jointly developed by Toyota and Daihatsu. It has 4 cylinders It is 997 cc. 4 valve per cylinder. Bore and stroke is 69x66.7 mm, with a compression ratio of 10.0:1. Output is 51.5 kW at 6000 rpm with 95 Nm of torque at 4000 rpm. It features VVT-i, off-set type crankshaft which reduces friction losses and narrow-angle valves. Engine weight of 68 kg; was achieved by using cast-iron cylinder block produced by cold-box method. Applications:

2SZ-FE

The 2SZ-FE is 1298 cc. Bore and stroke is 72x79.7 mm, with a compression ratio of 11.0:1. Output is 64 kW at 6000 rpm with 122 Nm of torque at 4200 rpm. Daihatsu's internal code for this engine is labeled as K3-DE/VE and the turbocharged version as K3-VET. The engine features VVT-i (except for K3-DE model). In China, this engine is usually known as the 4A13. Applications:

3SZ-VE

The 3SZ-VE is 1495 cc, introduced in October 2005. First installed in 2005 on the second generation Daihatsu Terios. Bore and stroke is 72x91.8 mm, with a compression ratio of 10.0:1 and redline of 6500 rpm. Output is 80 kW at 6000 rpm with 141 Nm of torque at 4400 rpm. Commercial variant in Daihatsu Luxio and Daihatsu Gran Max has output of 97 PS at 6000 rpm with 13.7 kgm of torque at 4400 rpm. It features VVT-i. Applications: