Tow Test: Mercedes-Benz ML55 AMG

The Mercedes-Benz ML55 AMG is a high-performance towing machine.

When it was introduced two years ago, the Mercedes-Benz ML sport ute suffered its share of teething problems. Its fit and finish, as well as its durability, were not what we have come to expect from Mercedes. After a 40,000-mile test of a V-8-equipped ML430, our sister magazine, Car and Driver, noted that it was "very disappointed" with the truck's squeaks and rattles. Its customers ranked its quality well below average as well.

For the 2000 model year, Mercedes made some major improvements: The interior has been significantly up-graded; a new five-speed automatic transmission has been installed; and all regularly scheduled maintenance for the first four years or 50,000 miles is included with the purchase.

Perhaps motivated by BMW's new SUV, Mercedes has designed a special hot edition, the ML55, which had its chassis and engine tuned by AMG, Mercedes' racing partner. The engine is a thoroughbred 5.4-liter V-8 pumping out a lusty 342 hp. Wheels, tires, and brakes have been upgraded to handle a 140-mph top speed and 0-to-60-mph acceleration in seven seconds - or less.

The ML55 looks the part: dual hood ripples, twin exhaust pipes, racy red brake calipers, and bold lower-body cladding. Its interior is swathed in fine leather, burled walnut, and embroidered floor mats.

Leg the throttle and this Mercedes disappears. The ride is firm but rarely harsh. Body roll? Negligible. Its fat Dunlop tires do an excellent job holding down this two-and-a-half-ton meteor through tight turns.

Our test rig - a 20 1/2' Thompson Carrera and a single-axle trailer - weighed within 300 pounds of the ML55's 5,000-pound tow rating. Still, acceleration was remarkable. The ML55 hauled its load to 60 mph in less than 13 seconds, which is a feat I've never seen another SUV match. Traction at the launch ramp was also excellent - there's an electronic system that automatically brakes any wheel that begins to slip. Hit the low-range button and you get enough oomph to beach a whale. We measured fuel efficiency at 9 mpg, which is quite reasonable considering the load. Handling was sure-footed, aided by firm suspension settings and the wide tires. The tires aren't suitable for slippery winter weather or wet launch ramps, however.

I found the truck's entry awkward. I had to duck to keep from hitting my head. The climate-control system lacks a thermostat and is hard to operate. Also, you must adjust the radio by using a complex video screen that manages the truck's navigational system and optional cell phone as well. The price? A very elite $66,000.

MODEL Mercedes-Benz ML55 AMG
Engine 5.4-liter SOHC V-8
Net hp/rpm 342/5500
Net torque (ft-lb/rpm) 376/3000
Transmission 5-speed automatic
Front suspension control arms, torsion bars
Rear suspension control arms, coil springs
Wheelbase (in.) 111.0
Length (in.) 180.6
Width (in.) 72.2
Height (in.) 69.9
Brakes (front/rear) disc/drum; standard 4-wheel ABS
Tires Dunlop SP Sport high performance, 285/50WR-18
Curb weight (lbs.) 4,913
Towing capacity (lbs.) 5,000
Cargo capacity (min.-max. cu. ft.) 45-85
Fuel capacity (gal.) 23.7
Estimated city/highway towing fuel economy (mpg. avg.) 9
Price (as tested, estimated) $65,995

LAST WORD. Some flaws? Yes. But the ML55 is great for anyone who needs a vehicle with the guts of a real truck hidden inside some Porsche-grade excitement.