The E12 5 series was introduced in 1972. It was available as 4 door sedan. There were two models available: the 520 and 520i. Both models had a M10 four cylinder engine. The 520 had 115 HP and the 520i 130 HP. In 1973 the 525 came available. It had a six cylinder engine with 145 HP. A year later the 518 was introduced. This model had a four cylinder with just 90 HP. In that same year the 530i came available. It had a six cylinder engine. In 1975 a 528 six cylinder came available. It had 165 HP....