2007 Acura RDX & 2007 Mazda CX-7

It's official: The next big idea the auto industry's ready to exploit is compact SUVs that perform more like sport sedans. All right, so that's not such a new idea. But with recent fuel spikes and quite a few aging competitors in the segment, there may be an opportunity for someone new to take the lead. It may have been a small group at the time, but BMW earned the number-one spot several years ago in the compact premium-SUV segment with the addition of the X3, which was actually just a hair's breadth smaller than the midsize X5.

Now Acura takes aim.

On an entirely new platform, the 2007 RDX fits underneath the current mid-size MDX SUV in size and cost. And, when comparing specifications (length, width, height, track, turning diameter), the RDX is practically identical in every way with the X3. Acura even gave us an X3 at one point to run back-to-back comparison laps--but more on that later.

Acura's exterior design is simple and athletic, clearly meant to evoke its sportier personality. Generally speaking, the design looks like a low-slung new RAV4. The fast-raking windshield and racing-stripe style line running the length of the body, in addition to the wraparound rear glass and wind fin, add up to make the RDX appear quick. But it's more than just looks.

RDX buyers will get an all-new 2.3-liter turbocharged and intercooled I-4 engine that produces 240 horsepower at 6000 rpm and 260 pound-feet of torque at 4500 rpm. This latter number, although typically not all that important in small-SUV segments, is significant because the RDX makes more torque than any other vehicle in the current Acura or Honda lineup. Much of the credit should go to the turbocharger, which uses a unique "variable flow" approach to feeding the smaller turbo exhaust gases through two separate runners--a short one to spin the turbo quickly to reduce turbo lag, and a longer one to flow more air for higher-rpm passing power. On the intake side, the RDX channels air through the hood into an air-to-air intercooler before mixing fuel and cold air on its way to each cylinder. The large front-fascia inlet above the grille creates a type of ram effect to keep air constantly moving through the intercooler.

Off the line, RDX responsiveness is impressive and surprisingly smooth. Where some turbocharged engines tend to kick into first gear abruptly after a short lag, the RDX uses its new five-speed transmission, with a specially designed torque converter, to slip, smoothing out any hard hit while still offering a strong feel. The tranny has normal and sport settings as well as F1-style paddle shifters (right upshift, left downshift) on the back of the steering wheel, which can be used in either mode. The five-speed is quick to respond when enthusiastically run through the gears (paddles or stick), making it obvious that normal and sport mode have distinct personalities.