MZR is the brand name of a generation of Straight-4

Straight-4

The inline-four engine or straight-four engine is an internal combustion engine with all four cylinders mounted in a straight line, or plane along the crankcase. The single bank of cylinders may be oriented in either a vertical or an inclined plane with all the pistons driving a common crankshaft....

 engines engineered and built by the Mazda Motor Corporation

Mazda

is a Japanese automotive manufacturer based in Fuchū, Aki District, Hiroshima Prefecture, Japan.In 2007, Mazda produced almost 1.3 million vehicles for global sales...

 between 2001 and 2011. The MZR generation includes gasoline

Gasoline

Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...

 and diesel

Diesel engine

A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...

 powered engines ranging in displacements from 1.3L to 2.5L. All gasoline-powered MZRs feature an all-aluminum block construction with iron cylinder liners. The diesel MZR-CD engines use a cast-iron block (virtually identical to the Mazda F engine

Mazda F engine

The F engine family from Mazda is a mid-sized straight-4 piston engine with iron block, alloy head and belt-driven OHC. Introduced in 1983 as the 1.6L F6, this engine was found in the Mazda B-Series truck and Mazda G platform models such as Mazda 626 as well as many other models internationally...

) and an aluminum cylinder head.

There are three specific engine families within the MZR which include:

1. the small 1.3L to 1.6L Mazda Z-engine
   Mazda Z engine
   The Mazda Z-series is a smaller inline 4-cylinder gasoline engine ranging in displacements from 1.3L to 1.6L. They are the evolution of the cast-iron block B-engine....
   
   ,
2. the mid-sized 1.8L to 2.5L Mazda L-engine
   Mazda L engine
   The Mazda L-series is a mid-sized inline 4-cylinder gasoline engine ranging in displacements from 1.8L to 2.5L. Introduced in 2001, they are the evolution of the cast-iron block F-engine...
   
   , and
3. the 2.0L and 2.2L common-rail diesel Mazda R-engine.

Each engine has its own engine code and for accuracy should be identified with such.

The DISI turbocharged MZR L3-VDT was on the Ward's 10 Best Engines

Ward's 10 Best Engines

Ward's 10 Best Engines is an annual list of the ten "best" automobile engines available in the U.S. market, that are selected by Ward's AutoWorld magazine. The list was started in 1994, and has been drawn every year since then....

 list for 3 consecutive years for 2006, 2007 and 2008.

The Ford Motor Company

Ford Motor Company

Ford Motor Company is an American multinational automaker based in Dearborn, Michigan, a suburb of Detroit. The automaker was founded by Henry Ford and incorporated on June 16, 1903. In addition to the Ford and Lincoln brands, Ford also owns a small stake in Mazda in Japan and Aston Martin in the UK...

 owns rights to build and use the MZR generation of engines under their Duratec brand name for global service in its vehicles since 2003.

As of 2011, Mazda discontinued development of the MZR generation of engines to be replaced by their new SkyActiv generation of engines.