Rumored to be based on BMW's excellent twin-turbo V-8 standard on the new 2009 7 Series, the presumably turbocharged V-12 could be used by Benz in both uplevel S-Class models as well as the Maybach. While the current Benz twin-turbo V-12 is an undoubtedly smooth powerhouse delivering unbelievable levels of torque and performance that move the Maybach's avoirdupois with alacrity (0-60 mph in the five second neighborhood), the Benz V-12 remains an old design with a relatively inefficient 3-valve-per-cylinder head that's a holdover from the firm's previous-generation V-8. That 3-valve, twin spark plug head was brought to market a decade or so ago to help Benz meet emissions standards, but has been abandoned for the new 5.5- and 6.2-liter V-8s with a four-valve-per-cylinder design that breathes better and revs freely.
Why Benz is not developing its own V-12 is unknown, but perhaps the firm feels it has already invested enough cash in the slow-selling Maybach brand.
In an addendum to yesterday's rumor of an Aston and Mercedes deal, BMW's Draeger also claim they are in talks with Aston Martin (me too!). Perhaps all three companies would have a say in the design of the new Maybach? BMW also claim they are ready to sell their diesel engine technology (upcoming 335d and X5 xDrive 35d) to an American carmaker needing a smaller clean diesel for use in their passenger car fleet.--Colin Mathews