Car Magazine, which snapped these shots, is reporting that the 2011 M5 will gain a breathed-on version of the BMW X6's 4.4-liter twin-turbo V8 producing a whopping 540 HP. Why? The current V10, despised by some but loved by others for its quirky rev-happy nature, will only meet emissions regulations for two more years. If the big V8 does find its way into the M5, expect a much lower revving, torquier drive. The magazine also reports that the M5 is likely to be manumatic only, which doesn't come as a surprise, but is still pretty disappointing. [via Car Magazine]