BMW's X5 is fast, comfortable, and prestigious. It delivers superb handling and excellent performance. As if its 4.4i wasn't quick enough, BMW has introduced a 347-horsepower 4.6is model. Logically, the X5 makes little sense. It is not highly capable off road when measured against other capable sport-utilities. It offers less cargo capacity than a 5 Series wagon with an uncomfortably high load floor. It does not offer quite the on-road performance, handling or braking of a sports sedan or sports wagon in their respective price ranges. Logic may not be the key factor here, however. The X5 is sporty and stylish, often attracting attention. It's quick. It works well in foul weather. And it offers that commanding seating position that many people like. It also has that twin-kidney grille and BMW's reputation for quality and driving excitement. Perhaps those are among the reasons X5 sales are strong. BMW sold more than 40,000 X5s during the 2001 calendar year. The new BMW X5 4.6is model takes SUV performance to new heights with a powerful V8 that delivers 0-60 mph acceleration times in the 6.5-second range, which is very quick, indeed. It offers a potential top speed of nearly 150 mph, which is seriously fast for a vehicle this large. Massive tires offer impressive cornering grip and stopping power. It may be the best-handling SUV on the road. Muddy trails are easily negotiable. Inside, it's luxurious and comfortable.