Powertrain and Performance: We head to the track
If you were to look only at the basics of these two SUVs, you would conclude that they are pretty evenly matched. The Infiniti is powered by a 5.6-liter V-8 engine mated to a seven-speed automatic, the Lexus has a 5.7-liter V-8 with a six-speed auto, and both have standard four-wheel drive with a low-range transfer case. Look past the surface, though, and you'll discover that these two are very different beasts.
The Infiniti QX56 is the athlete of the two. Though it is slightly longer, wider, and taller than the Lexus, it's 145 pounds lighter, and its V-8 pumps out 400 horsepower versus the LX570's 383 horsepower; the Infiniti tops the Lexus in torque, too, with 413 pound-feet, 10 more than the Lexus.
When we headed to our test track, the Infiniti QX56's extra power and lower weight became more apparent. We measured the run from 0 to 60 mph in 6.6 seconds, which was 1.7 seconds quicker than the Lexus LX. Not many QX56s and LX570s will see drag strips, but our Infiniti polished off the quarter-mile run in a respectable 14.9 seconds at 94 mph, topping the Lexus LX570's best run of 15.3 seconds at 91 mph. In our braking tests, the QX56 stopped in 166 feet, 14 feet sooner than the LX570.
Equipped with such large engines, both SUVs suck fuel. The Infiniti manages to wring a few extra miles out of each gallon of premium gasoline with a best-in-class EPA rating of 14/20 mpg city/highway; the Lexus is rated at 12/18 mpg. In a combination of stop-and-go suburbia and freeways, our mileage from both of the sport-utilities averaged 15 mpg, according to the trip computers.
Advantage: Infiniti QX56