Yahoo Autos Tested: 2000 Mercedes-Benz ML55 Brings AMG into the SUV Fold
From the December 1999 issue of Car and Driver.
Think back to 1995. In a world of Ford Explorers and Jeep Grand Cherokees, did you ever imagine the emergence of today's Cadillac, Lincoln, Lexus, Infiniti, and Mercedes luxury sport-utility vehicles? Five years ago, a luxury SUV seemed as likely as a former WWF star's becoming a governor.
Well, it's happened. Luxury SUVs such as the Lincoln Navigator, the Cadillac Escalade, the Lexus RX300, and the Infiniti QX4 are littering parking lots at country clubs and grocery stores across the nation. And now, Mercedes brings AMG hammer power to the sport-utility class with its ML55 AMG.
The soul of this super-ute dwells in its engine. AMG starts with the 5.0-Iiter 24-valve V-8 from the SL500 and S500 and adds a stroked, forged-steel crankshaft that, in turn, adds nearly a third of an inch to the stroke, pumping displacement from 4966 to 5439cc. (Yes, by inflating 5439cc to 5.5 liters, Mercedes has co-opted Ford's truth-in-displacement badging ethic.) The ML55's 5.4-liter V-8 makes 342 horsepower at 5500 rpm, which is 74 horses more than in the ML430. AMG added a larger cross section to the magnesium intake manifold to increase airflow, replaced the hollow-cast camshafts with even lighter modular ones, and increased the stiffness of the valve springs.
With all this tuning, our ML55 test vehicle sprinted from zero to 60 mph in 6.8 seconds, 1.6 seconds faster than an ML430. The quarter-mile blew by in 15.3 seconds at 92 mph, or 1.3 seconds and 6 mph better than its non-AMG sibling. We clocked the ML55's top speed at 141 mph, making it the fastest SUV in the world. Impressive numbers for a 4913-pound truck. Fuel-economy estimates suffer only slightly. The EPA figures for the ML55 are 14/18 mpg city/highway. The ML430's is 15/19 mpg.
AMG didn't tinker as much with the ML's existing independent front and rear suspensions. Stiffened dampers, front torsion bars, and high-performance summer tires—Dunlop SP Sport 9000s, sized 285/50WR-18, with a tread pattern that looks like it belongs on a Porsche—are the only changes made that affect handling. The ML55 also sits on hefty-looking five-spoke, 18-inch aluminum wheels. With these changes, the ML55 stands 0.8 inch lower than lesser MLs. On the skidpad, the ML55 scored 0.74 g of grip. Surprisingly, that ranks it just 0.01 g ahead of the ML430.
We noticed only a little body roll while driving on tight, two-lane country roads in North Carolina, but the tires squealed a bit earlier than we expected. Spirited driving also reminded us that even with the high-performance engine, suspension, and tires, the ML55 is still a sport-utility vehicle with a high center of gravity. All the performance add-ons in the world can't make a tall SUV body feel as buttoned-down and secure as a sports car.
Unfortunately, we didn't get a chance to drive an ML55 on wet or snowy roads, but the aggressive tread pattern makes us fear the worst. Judging by experiences with our long-term Lexus RX300 and ML430, tires are absolutely critical for grabbing traction in bad weather, even with four-wheel drive. A good set of winter tires, we think, would be mandatory for any ML55 driven in the snow.
