The L-engine uses a chain-driven DOHC, 16-valve valvetrain with an all-aluminum block construction and cast-iron cylinder liners.

Other features include fracture-split forged powder metal connecting rods and a one-piece cast crankshaft.

Other features are intake cam-phasing VVT, VTCS, VICS, a stainless steel 4:1 exhaust manifold and a lower main bearing cage for increased block rigidity.

The SCi engines were designed at Ford's Cologne facility and assembled in Valencia, Spain.

The 2.0-litre (1,999 cc; 122.0 cu in) version has 10:1 compression ratio, an 87.5 mm (3.44 in) bore and it shares the 83.1 mm (3.27 in) stroke of the 1.8 L. Changes to the engine include switching from a cast aluminum to a reinforced plastic intake manifold and in 2011 fuel delivery was updated from Sequential multi-port fuel injection to gasoline direct injection.

The 2009 Focus had 143 hp (107 kW; 145 PS) when equipped with manual transmission due to a higher flowing exhaust system pulled from the 2006/2007 models.

[2] Mazda's LF-VD version was equipped with Direct Injection Spark Ignition (DISI) and a higher compression ratio for improved efficiency in the JDM and EDM markets.

The plastic intake manifold on early versions of the 1.8 and 2.0 has a major fault due to poor-quality materials.

Early four-cylinder Duratec engines can be ruined when the swirlplates break off and enter a cylinder.

The 23EW was built in Chihuahua, Mexico for transverse installation in several front-drive Ford/Mercury/Mazda vehicles through the 2009 model year.

An iVCT (intake variable cam timing)-equipped DOHC 16V version was used in the 2006–2009 Ford Fusion/Mercury Milan, and several generations of CD2-based crossovers.

These engines are tuned for torque-bias making them suitable for light-truck use and are not equipped with iVCT or VICS.

A high-efficiency Atkinson cycle version was used in the Ford Escape, Mercury Mariner, and Mazda Tribute Hybrids.

[citation needed] In 2010 the L3-VDT was revised to fix some of the common failures: the shape of the cylinder head was reworked, possibly to concentrate fuel near the sparkplug, the ECU was made faster and featured more air/fuel cells to reduce the chance of the engine leaning out.

The EcoBoost engines have different turbochargers, Ford-designed heads, different direct injection systems along with featuring Ford's Ti-VCT variable valve timing system instead of Mazda's S-VT.[9] Introduced in non-North American markets for the MY2008 and North American markets for MY2009, the 2.5 L L5-VE is an updated, bored and stroked version of the L3-VE 2.3 L. The 2.5 L; 151.8 cu in (2,488 cc) L5 4-cylinder engine has an 89 mm (3.50 in) bore and a 100 mm (3.94 in) stroke, with a compression ratio of 9.7:1.

[citation needed] They also used this variant under the Duratec engine family name in the 2010-2019 Ford Fusion.

In late 2006, Mazda announced an agreement with Advanced Engine Research (AER) to develop the MZR-R motor for sports car racing.