received Central Fuel Injection (CFI), which reduced power to . Ford addressed the power decrease in the base engine by releasing the HSO version for performance-oriented variants of the Tempo (GLS) and Topaz (LTS/XR5). A switch to multi-port fuel injection in 1988 raised horsepower to . Sequential fuel injection was added for 1992, increasing horsepower to . That same year the HSO variant was dropped, as the sportier versions of the Tempo/Topaz received the 3.0 L Vulcan as standard equipment. Applications: 1984–1994 Ford Tempo 1984–1994 Mercury Topaz 2.5 L A 2.5 L HSC version appeared in 1986. Its displacement resulted from its longer stroke. The engine block's deck height was raised to from the of the 2.3 L. The extra displacement was deemed necessary for it to serve as a four-cylinder engine option for fleet customers of the new Ford Taurus. This engine used the head and camshaft from the HSO engine and produced and . It sold in low volumes (less than 15% of the HSC engines built) and was costly due to the tooling changeover required for the taller deck height. The earliest 2.5 L came standard with electronic multi-port fuel injection. It received sequential fuel injection in 1991, raising output to and of torque. Applications: 1986–1991 Ford Taurus 1986 Mercury Sable References See also List of Ford engines HSC Gasoline engines by model Straight-four engines