The first Zetec-branded engine was the Zeta family, introduced for the 1992 model year powering the fifth generation of the European Ford Escort, the third generation Orion and the Mk.3 Ford Fiesta. The engine was originally available in 1.6 and 1.8 liter versions with a 2.0 liter version appearing in 1993 in the all-new Mondeo. The "Zeta" name was dropped in favour of "Zetec" when Italian car maker Lancia threatened to sue Ford for trademark infringement. The codename "Zeta" was originally used for the design of the cylinder head. A number of different systems were evaluated, and each one had a different codename using the Greek alphabet. The Zeta concept was the winner and the 4-valve-per-cylinder, DOHC design was used for the head of the replacement for the CVH in Europe and the US. The original manufacturing plan involved replacing the Dearborn manufactured CVH with Zeta. This resulted in the need to retain much of the architecture of the US CVH block. However, later in the development process, the plan was changed and the Chihuahua engine plant in Mexico was rebuilt to allow manufacture of the US engines. For Europe the decision was taken to build Zetas in Bridgend (Replacing CVH) and in Cologne. The US (2.0L) and European base engines were almost identical. However, crucially, the US management insisted that the US engines had to be "freewheeling", or a non-interference engine design. The fuel economy penalty with the freewheeling system (around 1–2%) was considered to be too great for European engines. The result was that the engines used different pistons. Another difference was that the US engines featured sinter forged connecting rods versus conventional cast rods in Europe.

Early versions of the engine had a problem with sticking valves – far more evident in the UK (and in cold climates), where a driving style with earlier gear changes is more common than on the Continent – unless a special Ford formulation of oil was used. After small changes in 1995 to fix this problem the engine was known as the Zetec-E. This engine received a plastic inlet manifold and EGR derived from the Mondeo.

The Zetec had another redesign in 1998. This version, the Zetec-R, had a two-piece crankcase which helped damp out noise and vibration, conventional tappets with shims rather than hydraulic ones, and longer connecting rods with a lower piston compression height. This engine was used in turbocharged form in the Focus RS and had 212 bhp (158 kW; 215 PS) (dubbed Duratec RS). It was also used in the Focus ST170 with a cylinder head modified by Cosworth with Variable Valve Timing on the inlet cam and had 170 bhp (127 kW; 172 PS).

The Zetec can be identified by having a silver cam cover with "DOHC 16v" on the bottom left. The Zetec-E has "ZETEC 16v" on the bottom left, and the Zetec-R has a black plastic cam cover. The Focus RS and ST170 (SVT) are both Zetec-R engines, despite being branded Duratec.

Production of the Zeta family lasted from September 1991 through December 2004. Displacement ranged from 1.6 L to 2.0 L.

Above "Stolen" from Wiki