The Saab H engine is a redesign of the Saab B engine, which in turn was based on the Triumph Slant-4 engine.Despite the name it is not an H engine or horizontally opposed engine, but a slanted inline-4. The H engine was introduced in 1981 in the Saab 900 and was also used in the Saab 99 from 1982 onwards and the Saab 90. It continued in use in the 900/9-3, 9000, and 9-5. The 2003 GM Epsilon-based 9-3 switched to the GM Ecotec engine, leaving the 9-5 as the sole user of the H engine.