The first time we got a peak at BMW's 5-series executive mid-size offering was in 1975 when they brought the E12 chassis to North America. It was a 530i, but two years later replaced by the 528i. The BMW 528i was a decently powered by a 2.8L 6-cylinder engine putting out 179hp, and equipped with lots of the bells and whistles expected from a luxury car. Emissions regulations forced some power reductions when compared to their European counterparts, but not by much. The 528i took a long hiatus, and then returned as an E39 in 1997. Though the engine actually lost a couple of ponies, the strength of the unibody chassis and precision BMW 528i parts that made up its suspension made a vast improvement to handling and safety. By this time, the luxuries that were considered "bells and whistles" in the 1970's were now standard. Improvements to this design were made on the E60 chassis in 2007, and any BMW 528i owner of the E60 recognizes its best-in-class features and the performance of the 227hp engine. You wouldn't think that improvements could be made to this stellar vehicle, but in 2010 the F10 chassis dropped and now the BMW 528i was producing a beastly 254hp (this time with a 3.0L straight 6-cylinder engine). Overall size and curb weight increased however - but that's the price you pay for luxury. Fun fact: the standard A/C compressor found on the first E12 models was made by Behr, and was purported to be too weak for the North American market. Rumor has it, BMW sent two engineers on a summer road trip through Texas in a black BMW E12 with disabled power windows.