Main article: BMW E24
The original 6 Series was the successor to the E9 coupés, namely the 2800CS, 3.0CS and 3.0CSi. The new E24 chassis was safer than that of the E9, meeting new United States federal crash and rollover standards. The original 6-Series was first launched in August 1976. This car had a 3210cc engine with 197PS (145kW). In 1980 debuted the 635CSi, with a 3453cc SOHC, 218PS (160kW) engine and a top speed of 222km/h (138mph). The 635CSi could reach 100km/h (62mph) in 7.4 seconds. A luxury version, known as the L6 arrived in 1987 with leather headliner and trim and other accoutrements.
In 1983 BMW took the M88/3, a modified version of the M88/1 from the BMW M1 and put it in the E24 chassis, creating the M635CSi, or M6. This had a DOHC 24-valve 3453cc, 286PS (210kW) engine, taken from the BMW M1 with a top speed of 255km/h (158mph). The M6 reached 100km/h in 6.2 seconds. The M6 also had improved suspension, brakes, and a close-ratio manual transmission.
Main article: BMW E63/E64
An all-new 6-Series (E63) was introduced in 2003, filling the hole in the lineup left since the end of the 8-Series' production. Based on the underpinnings of the E60, the new 6-Series was introduced with a 4.4L 325 hp V8 engine for the 645Ci. In 2004, a more affordable inline six-cylinder engine was introduced in the 630i. This was soon followed by a convertible model (the E64), the first 6-Series with a removable top. Soon after its introduction, the 645Ci was replaced by the 650i, with a larger displacement (4.8L) and 360 hp. The range-topping M6 arrived in late 2005, using the same V10 engine as the M5, with 507PS (373kW). In 2007 the 635d (Twin Turbo 3.0L Diesel) was introduced with 290 bhp and 430 lb ft which comprehensively outguns the 630i with the added bonus of 41mpg, the 635d Convertible (released shortly afterwards) was described by Autocar as "the best 6-series of the lot."
- 2004-2005 645Ci - 4.4L V8, 333hp.
- 2004-2005 645Ci Convertible - 4.4L V8, 333hp.
- 2005- 630i- 3.0L I6, 254hp.
- 2006- 650i - 4.8L V8, 360hp.
- 2006- 650i Convertible - 4.8L V8, 360hp.
- 2007- M6 - 5.0L V10, 507hp.
- 2007- M6 Convertible - 5.0L V10, 507hp.
- 2007- 635d- 3.0L Twin Turbo Diesel I6, 290hp.
- 2007- 635d Convertible- 3.0L Twin Turbo Diesel I6, 290hp.
- 2008/9- 635i- 3.0L Twin Turbo I6, 306hp.