Instrumented Test
Mercedes-Benz, like many other carmakers, is embracing the turbocharger en masse in reaction to calls for greater fuel efficiency. Smaller, forced-induction mills are spreading throughout the three-pointed star’s lineup; the only naturally aspirated holdouts are the company’s gasoline V-6s and the mighty 6.2-liter V-8 found in select AMG models. Although such high-tech downsizing rarely comes without a cost—be it sticker shock, underwhelming performance, or overpromised fuel-economy ratings—this 2012 E550 4MATIC sedan seems to pay no penalty.
More of a Good Thing, Less Guilt
The all-wheel-drive E550’s base price of $60,665 is decidedly not cheap, but it’s a scant $190 higher than last year’s model’s, and you now get the company’s new 4.7-liter V-8 with twin turbos and direct injection. It’s good for 402 hp and 443 lb-ft of torque from just 1800 rpm—that’s 20 hp and 52 lb-ft more than last year’s nonboosted 5.5-liter eight-cylinder.
With the aid of now standard all-wheel drive, the additional power is enough to shave at least 0.5 second off a 2010 E550’s 0-to-60-mph and quarter-mile times, with the former now taking 4.3 seconds and the latter passing in 12.8 at 112 mph. Despite the power bump and extra mass of the all-wheel-drive gear (this E550 weighed in at 4411 pounds, 173 more than the last E550 we tested), fuel economy improves from an EPA-rated 15 mpg in the city and 23 on the highway to 16/26. Our heavy-footed average increased from 16 mpg to 18 mpg, too.
Slipping Away
One difference we could do without, however, was the fitment of 18-inch Pirelli P Zero Nero all-season tires (sized 245/40) on our test car in place of the Continental ContiProContact all-seasons that were on the last E550 4MATIC we evaluated.
With the new car’s added weight and the Pirellis reducing the chassis’s grasp on the road to a gentle hug, 70-mph panic stops stretch from 169 feet to 180, and lateral grip slips from 0.86 g to a meager 0.81. Although both tires are authorized original equipment, Mercedes admits that availability at the time of production largely determines which set is installed on a particular car. Unfortunately, there’s no way to determine which brand a particular car will have until it’s off-loaded at the dealership.
