BMW launched an innovative engine concept in the marketplace with the BMW eta concept in 1981 and this significantly reduced consumption. The engine was based on the 2 litre six-cylinder engine but now had a displacement of 2.7 litres and was designed with maximum torque at lower revs. The 528e consumed 9% less fuel by comparison with the BMW 520i while having improved acceleration values. This concept was initially only supplied in the USA and Japan before it was also supplied in the European market in the BMW 525e from 1983.