New 2007 Mercedes-Benz SLK350

The Porsche Boxster and the BMW Z4 are about to get their comeuppance. Later this year, at some multilane intersection somewhere in these United States, an unsuspecting Boxster S driver is going to glance into the next lane and see a 2005 Mercedes-Benz SLK, its new, 3.5-liter, 24-valve V-6 burbling under the newly sculpted hood. The Porsche owner, accustomed to treating SLKs with the contempt usually reserved for a buzzing fly, will regard the new Benz with only casual and condescending interest. But then he will notice the SLK driver's look of keen anticipation, and suddenly it will dawn on him that, laughable as it may seem, his precious Porsche is being invited to participate in the latest round of the world's longest race, the stoplight grand prix. With an SLK! A car that for years has been the wimpiest, girliest little German roadster this side of an Audi TT. Wouldn't it be cool to be at that intersection and see that Porsche driver's face the first time a 2005 Mercedes-Benz SLK350 smokes his butt into yesterday?

OK, we might be
stretching a bit. Mercedes estimates a 0-to-60-mph time of 5.5 seconds for the new SLK350, which is at least fully competitive with the Boxster S and the Z4, if not literally fast enough to beat them. The little Merc is no longer an effete, poseur mall crawler; and no longer is its retractable hard top its principal virtue. It's now a real, honest-to-Hans sports car, and it finally looks like one, too.

The SLK's transformation started with its body and chassis, seriously weak and flabby in the outgoing car. On paper, the improvements are expressed as 46 percent greater torsional rigidity and a nearly 20 percent increase in bending stiffness, partly the results of a body shell made from a new cocktail of high-tensile steel, aluminum, and magnesium, with a few garnishes of fiber-reinforced plastic. On the road, progress is measured by a chatty chassis that incessantly tells the driver what's going on under those four Pirelli P Zero contact patches. For anyone who has spent time in the first SLK, pushing the new car over a challenging road will be a revelation. It feels, sounds, and acts like a thoroughbred.

The SLK's stiffer body cradles improved suspension, steering, and brakes, as well as a new powertrain. The previous control-arm front suspension has been replaced by a strut-type design, which provides well-snubbed damping and good ride comfort. Rack-and-pinion steering replaces the recirculating-ball format. The SLK doesn't match the Boxster's steering feel and feedback, but it's on par with the Z4 and far surpasses the TT. In the mountain switchbacks of Mallorca, where we had to keep decelerating for hundreds of professional cyclists grinding up hillsides in preparation for the Tour de France, the powerful brakes never faded.

We have few fond memories of the original SLK's supercharged, 185-horsepower, 2.3-liter four-cylinder engine, which delivered reasonable performance but always sounded as if it had a bad cold. That problem was addressed originally by the introduction in 2001 of the optional 215-horsepower, 3.2-liter V-6 and then in 2002 with the SLK32 AMG's supercharged, 349-horsepower V-6. Yet no matter how much power was speaking up from under the hood, the SLK's complaisant chassis was, unfortunately, dominating the conversation. For 2005, Mercedes ditches the raspy blown four altogether, and we doubt any tears will be shed over the loss.

New 2007 Mazda CX-7

Do you have the patience to hear about one more SUV? How about one of those annoyingly nebulous SUV/crossover/whatever vehicles? At the risk of having you turn the page right now, we'll tell you that the new Mazda CX-7 is an SUV-like thing that tries to be sporty. We know, you've heard that before, with the BMW X5 and X3, the Infiniti FX45, the Porsche Cayenne, the Jeep Grand Cherokee SRT8, and some lesser lights as well.

Look past the obvious-the RX-8 wannabe front fenders, the hop-up windowline, and the bulging rear wheel arches-and you notice that, unlike every other entry in this overcrowded field (save perhaps the FX45), the CX-7 has not a single flat plane anywhere on its body. The front end is radically swept back, the windshield sports the fastest rake in its class, the roofline takes a dive aft of the B-pillars, and even the greenhouse features some major tumblehome and tapers in toward the rear. This thing isn't just styled, it's shaped.

The CX-7's engine is equally radical. Borrowing the Mazdaspeed 6's direct-injection, 2.3-liter turbo four-a high-strung engine with an all-or-nothing, turbo-dependent power delivery-and pairing it with a manu-matic transmission sounds like an absurd choice for SUV duty. After driving the CX-7, we'd say it's merely unusual. In this application, the engine has traded away 30 hp and 22 lb-ft for improved driveability, yet it's still able to push the CX-7 along with verve while returning semirespectable economy ratings of 18/24 mpg (with all-wheel drive). But the throttle response is hardly linear, and the engine note will never be mistaken for the smooth spin of a good V-6.

The CX-7's sporty chassis tuning suffers no such downside. Its most immediately endearing quality is the steering response, which is direct, linear, and nicely weighted. SUVs that don't heel over in corners are no longer a novelty, but even in those vehicles you're keenly aware that a lot of weight is riding way up high. The CX-7 is a bit lower and lighter (under two tons, anyway), and it manages to escape that high 'n' heavy feeling.

Naturally, the CX-7 isn't quite as roomy as some of the boxier entries, even though it's longer and wider than the Mazda Tribute, and there's no third-row seat. (That's coming in the CX-9, which was recently unveiled at the New York auto show.) The CX-7's below-the-windowline cargo space is reasonable, but its tapered greenhouse and sloping roofline cut into maximum capacity. If hauling stuff is your priority, you have a herd of more suitable SUVs to pick from. The CX-7 instead makes a case for itself as a tall, sporty wagon-and, for less than $30,000 (exercising a modicum of options restraint), it's notably cheaper than the other sporty crossovers at the auto mall. That's how you wedge your way into an overcrowded field.

New 2007 Acura RDX

"There are two vehicles that I know really, really well," Gary Evert says as we pitch the RDX into a downhill left-hander in Mount Tamalpais State Park north of San Francisco. "The RDX and the BMW X3."

There was plenty for Evert, the RDX's chief engineer, to learn from the X3, both from the BMW's achievements and its failures. For example, the X3's six-cylinder engines position it too closely in performance and price to the X5, so Acura decided to restrict its V-6 to the bigger MDX. The RDX instead gets Honda's first production-car turbo engine in the United States. Based on the 2.4-liter unit from the TSX sedan, the new turbo four produces 240 hp and 260 lb-ft of torque.

This engine is a winner, and its debut will prove to be a watershed moment for the hard-core Honda enthusiasts who can rattle off engine codes as easily as their birth dates. Turbo lag barely exists, power delivery is linear and strong, and fuel economy is estimated at 19/24 mpg city/highway. Our test vehicle's engine emitted a low-frequency drone when we decelerated, but Evert assured us that final production tweaks of the ECU would take care of that. After we headed out of San Francisco, the RDX surged through the Golden Gate National Recreation Area's hills with such ease, we actually forgot that there was a turbocharger under the hood.

Acura mates the turbo engine only to a five-speed automatic, but paddle shifters rip off crisp gearchanges. The standard all-wheel-drive system is adapted from the RL sedan. It delivers up to 70 percent of the torque to the rear axle, where it can be diverted entirely to either rear wheel, an effect that is easily discerned if you really push the RDX through a corner. The Acura might not be as sporty as the X3, but its accurate steering and buttoned-down body control are joined by a firm, reasonably supple ride that doesn't beat you up like the overly stiff BMW's does.

The RDX will share its body and chassis with the new Honda CR-V, but it won't share its all-wheel-drive system. The turbo engine also will be an RDX exclusive for now, but it certainly deserves to spread to other vehicles in the Acura and Honda stables.