BMW replaced the twin-turbo N54 with the single-turbo N55 in 2010, but would bring the N54 back in souped-up form for a special-edition 3-Series the following year.

A single turbo kit would be the ideal thing to do, but it would make the car instantly illegal in several states. It’s simpler, better at making power, and is much more reliable. The catch is ...

Visit Car and Driver to research 2011 BMW X6 to Get Single-Turbo N55 Inline-6, 8-Speed Transmission - Article. ... The N54 twin-turbo engine is not going away. Instead, ...

Other vehicles that use the same N54 3.0L twin-turbo six, such as the X6, 135i, as well as 3-series and 5-series models produced from March onwards are not affected.

For 2011, BMW dropped the N54 twin-turbocharged 3.0-liter inline-six and replaced it with the N55 single-turbo 3.0-liter.

BMW replaced the twin-turbo N54 with the single-turbo N55 in 2010, ... upgraded the interior, and slapped an M Sport body kit on top of the 335i's already refreshed exterior.