The Toyota NZ engine family is a straight-4 piston engine series. The 1NZ series uses aluminum engine blocks and DOHC cylinder heads. It also uses sequential fuel injection, and has 4 valves per cylinder with VVT-i. The engines are produced by Toyota's Kamigo Plant in Toyota, Aichi, Japan (1NZ for Prius, NZ for Vitz and ist, and for Sienta); by Siam Toyota Manufacturing in Chonburi, Thailand (NZ for NBC cars such as the 1NZ-FE for the Yaris and Vios); and by Indus Motor Company in Karachi, Pakistan (2NZ for Corolla). 1NZ-FXE The 1NZ-FXE is a hybrid version. Bore and stroke is . It features forged steel connecting rods and an aluminum intake manifold. The engine has a high physical compression ratio of 13.0:1, but the closing of the inlet valve is delayed, for an effective compression ratio of 9.5:1. The net result is that the engine has a greater effective expansion than compression—making it a simulated Atkinson cycle, rather than a conventional Otto cycle. The reduction in cylinder charge means reduced torque and power output, but efficiency is increased. This combination makes the 1NZ-FXE suitable for use with the Hybrid Synergy Drive, where peak torque and power demands can be met by the electric motor and battery. Output is at 5000 rpm with of torque at 4000 rpm. Peak thermal efficiency is about 37%. Production was discontinued in 2009, with the arrival of the 3rd generation Prius, which replaced the 1NZ-FXE with the 2ZR-FXE. In 2012, upon the arrival of the Prius c (North America), the Aqua (Japan), and the Yaris Hybrid (Europe), an improved version was introduced. Without any belt-driven accessories, and a physical compression ratio of 13.4:1, the new version delivers an output of at 4800 rpm with of torque at 3600–4400 rpm. The 1NZ-FXE Hybrid Synergy Drive in the Toyota Prius has won several International Engine of the Year awards: Best Eco-friendly 2000 Best Eco-friendly 2001 Best Fuel Economy 2005 Best 1.4-litre to 1.8-litre 2005 Best Fuel Economy 2006 Best 1.4-litre to 1.8-litre 2006 Applications: Toyota Corolla (Axio/Fielder) Toyota Prius (XW10 & XW20) Toyota Prius c/Toyota Aqua Toyota Probox Toyota Sienta (XP170) Toyota Yaris 1NZ-FXP The 1NZ-FXP is a hybrid version. Bore and stroke is . It features forged steel connecting rods and an aluminum intake manifold. The engine has a high physical compression ratio of 13.0:1, but the closing of the inlet valve is delayed, for