Mercedes-Benz has taken a risk in its quest to downsize its engine range. For 2015, the brand’s popular M-Class five-passenger CUV did away with its trusty 4.4-liter, twin-turbocharged V8, and has replaced it with a 3.0-liter, twin-turbocharged V6.
It’s no surprise that power is down thanks to this move. Outputs of 402 horsepower and 443 pound-feet of torque are replaced by 329 hp and 354 lb-ft, but weight is down significantly as well. The new ML400 is nearly 300 pounds lighter than the 4,982-pound ML550. Will that tradeoff be enough to satisfy a buying public that’s embraced falling fuel prices by buying bigger and thirstier vehicles? To find out if the blown V6 is a suitable replacement for the twin-turbo V8, we spent a week at the helm of the all-new ML400.