When the first Touring models for the BMW 5 Series (E34) were introduced in September 1991, the BMW 520i also came onto the market. Right from the start, it was equipped with the advanced six-cylinder four-valve engines (M50B20). From 1992, the technically revised version (M50B20TU) was fitted, which was characterised by the use of VANOS technology. This facilitated control of the valve stroke in accordance with the temperature and load, and resulted in better consumption and fewer emissions. After the BMW 525tds, the BMW 520i Touring was the most popular Touring model in the series with more than 31,000 units being produced.