This week, Mercedes-Benz revealed details on its next-generation of high-efficiency engines, all-new motivators designed to deliver more pure performance and greater all-around operating efficiency. Both the 3.5-liter V6 and the 4.7-liter twin-turbocharged V8 feature modular architecture based around lightweight aluminum blocks/heads and a host of innovative features. They're were also created to be fully compatible with start-stop technology, M-B's 4MATIC all-wheel drive and the automaker's present and future hybrid systems.
Delivering exhilaration on demand
The first of these new engines to reach the U.S. will be the 4.7-liter twin-turbo V8 which will see its first application this fall in the 2011 Mercedes-Benz CL-Class. Although 15 percent smaller than the 5.5-liter that it replaces, this new double-overhead-camshaft motivator is rated at 429 horsepower and 516 lb.-ft. of torque -- gains of 12 percent and 32 percent, respectively, in those primary outputs. Using one ideally matched, air-to-water intercooled turbo per cylinder bank, Mercedes was able to increase torque output by more 45 percent at 2,000 rpm. In U.S. trim, it will deliver 100 percent of its peak twist between 1,800-3,500 revs. Of equal importance in the face of ever-tightening CAFE and emissions requirements, Mercedes estimates that this new V8 will offer about a 22-percent gain in fuel economy and a corresponding decrease in its CO2 output.
Key among the many other notable techno tweaks on this new V8 is a multi-spark/multi-program ignition system paired with high-pressure third-generation piezo-electric direct fuel injectors that ensure more complete combustion in all operating modes. Also contributing to the efficiency gains are more precise electronic controls for the variable camshaft timing, start/stop circuitry and transmission shift mapping; a reduction in parasitic losses from a new demand-controlled oil pump, optimized water pump, volume-controlled fuel pump and intelligent generator management plus various friction-reducing measures.
Due for deployment in Europe later this year, the all-new 3.5-liter twin-cam V6 won't see duty in America until sometime in 2011 at the earliest. But when it does arrive, this naturally-aspirated gasoline engine will bring its own kind of high-efficiency charm to any and all M-B models it does power. Unlike the current 3.5-liter, the new V6 has a 60-degree rather than a 90-degree V-angle, which makes it more compact and even smoother while eliminating the need for a balance shaft. Although lacking turbo enhancement - at least for the time being -- this new V6 shares virtually all of the technological innovations of the V8 and enjoys a similar bump in total performance.
Mercedes only presented Euro-spec output and fuel economy stats for the new V6, but the striking comparative upgrades provide a good idea of what we can expect when it does turn up here. Using the domestic S350 as a baseline, pony count jumps from 268 to 302 with the new 3.5-liter and its torque stat moves from 258 to 273 lb.-ft. -- with all of that on hand from 3,500-5,250 rpm. Mercedes internal test data shows the new V6 also nets a 24 percent gain in relative fuel economy and a commensurate drop in its CO2 emissions.