took AMG's performance modifications for a fast midsized sedan to a new level. AMG made the world's fastest passenger sedan at the time, nicknamed the Hammer, by squeezing Mercedes 5.6-litre V8 tuned by AMG to 360 hp into a midsized sedan. It was very aggressive for the era, with 32-valve cylinder heads and twin camshafts, and said to be faster than the Lamborghini Countach from 60 to 120 mph. Later models were even more powerful and introduced the 17-inch AMG Aero 1 Hammer wheels. 1986 was also the year Mercedes introduced the 560 M117 engine. This provided yet another opportunity for customers to order the largest AMG displacement available at the time, the 6L 100 mm bore SOHC or DOHC engines available for both the W126 coupe and sedans. Through the early 2000s, AMG focused principally on supercharged V8 and V6 engines, but the company officially abandoned this technology in 2006 with the introduction of the naturally aspirated 6.2 L M156 V8. On 16 January 2006, Mercedes-AMG Chairman Volker Mornhinweg told AutoWeek that the company would use turbocharging for higher output rather than supercharging. For 2011, AMG released the M157 5.5L bi-turbo V8, which has supplanted the M156 in its full-sized cars such as the S-Class and CL-Class (and is trickling down to the CLS, E-Class, and ML-class). In 2012, Mercedes-AMG Chairman Olla Kallenius said that Mercedes-AMG will not produce diesel engines to compete with BMW's tri-turbo diesels (BMW M Performance range). Although there were some AMG models in the 1980s with manual transmissions, almost all recent models have used automatics (5G-Tronic and later 7G-Tronic with Speedshift), in contrast to BMW M, which used manual and recently automatic transmissions (the current type being a dual clutch transmission). Starting in 2009, however, AMG began adopting the seven-speed AMG SpeedShift MCT automatic transmission. Although these are considered the most well known in-house tuning divisions, Mercedes-AMG has a considerably different philosophy than BMW M. Compared to BMW M, Mercedes-AMG is "less narrow in its sporting focus, yet still combining sledgehammer performance with relaxed handling, cultured comfort, and practicality". While founders Hans Werner Aufrecht and Erhard Melcher had emphasized proper racing cars, Mercedes-AMG had diverged considerably from this philosophy in recent years, with their offerings being well known for straight-line acceleration but poor handling dynamics. However, current Mercedes-AMG chairman Volker Mornhinweg has urged the division to return to its roots of building sports cars.