The tape measure reveals one of the few meaningful dimensional differences. While the height and width of all four vehicles fall within 1.1 inches of each other, the Lexus seems to have benefited from ads in the back of this magazine. At 187.8 inches long, the RX 350 has 5.6 inches on the XC60 and Q5 and is a whopping 9.5 inches longer than the GLK350.

Testing shows size isn't everything, as precious little separates our quartet at the track. In the sprint to 60 mph, a mere two-tenths of a second differentiate the quickest (Audi/6.6 seconds) from the two slowest (Volvo and Benz, 6.8). In the quarter mile, the Audi again bests the Volvo by two-tenths. The difference in lateral acceleration is even smaller; just 0.07 g distinguishes the stickiest (Audi/0.85 g) and most slippery (Lexus/0.78 g). Though the Audi has the largest disc brakes, braking honors go to the lightweight Benz. At 118 feet, the GLK stops two feet shorter than the Q5 and a full 13 feet ahead of the heavyweight RX.

Even a close exam of pricing yields only a slight advantage for the Benz. With a base price of $36,775, the GLK350 starts off roughly $1200-$1500 cheaper than its rivals, but all quickly head into the $40,000 range once a few options are tacked on.

So with each manufacturer's shot so tightly grouped on target, how do we tease out a winner? We head for the hills and then down into the desert -- in this case, Anza Borrego State Park, the largest in California. Coming along for the ride are Editor-at-Large Arthur St. Antoine, Road Test Editor Scott Mortara, and Senior Editor Ron Kiino.