Dynamically, the Crossfire turns out to be a mix of the familiar and the new. The eighteen-valve, 3.2-liter SOHC V-6 is a staple of the Mercedes lineup; in this application it makes 215 horsepower and 229 pound-feet of torque. The engine sounds better here, thanks to the Crossfire's unique, center-exiting exhaust. Peak torque comes on stream at 3000 rpm, which helps make the Crossfire sports car quick at low speeds. But open it up on the highway, and the rush doesn't continue with the same urgency. The four-wheel disc brakesaided by Mer-cedes' Corner Brake Control and Brake Assistdo a commendable job hauling the Crossfire down from extralegal speeds and are easy to modulate.
There is a choice of two transmissions. Chrysler gives the five-speed automatic its AutoStick label, but in fact this is the superior Mercedes Touch Shift unit, which can be manually up- and downshifted without first moving the selector out of drive. We would like to see steering-wheel-mounted shift paddles, however.
We found we preferred the smooth, smart autobox to the six-speed stick, whose stubby shift lever promises short, slick shifts, but whose linkage doesn't really deliver. And the clutch's long travel makes shifting for yourself feel more like work than play.
Like the powertrain and the brakes, the suspension is a Mercedes design as well, with upper and lower control arms up front and a multi-link setup at the rear. But the actual pieces used here are different, with unique spring heights, anti-roll bar diameters, bushings, spring rates, and shock valving.
We know the SLK to be not quite a sports car but more of a sunny-day tourer compared with the purist BMW Z4 or the Porsche Boxster. You get the sense that the Chrysler engineers wanted to take the Crossfire further. They tuned the suspension to be firmer, specified larger wheels, and opted for lower profile rubber: 225/40ZR-18 up front, 255/35ZR-19 at the rear. Both the high-performance and the available all-season tires are Z-rated.
Combine that chassis setup with the Cross-fire's ultra-rigid body (stiffer than that of the Porsche 911, the engineers brag) and you get a car that responds very well in hard driving. The Crossfire turns in sharply and corners flat. The ultrawide tires provide so much grip (even the all-season Continentals), that, even with the stability control switched off, it's hard to find their limit. Yet, despite the tires' low aspect ratios and the aggressive suspension tuning, the ride isn't too harsh. The only missing element here is some involvement from the helm. Unfortunately, the Mercedes recirculating-ball steering unit can't hope to match the feel of the best sports cars' (Boxster, Z4, Nissan 350Z).
Still, the Crossfire is the sportiest Chrysler ever, and that's a good thing. We're not sure what Chrysler's use of Mercedes componentry will do for the Mercedes brand, but it's certainly good news for Chrysler. And if parts sharing helps make an exciting concept like the Crossfire a showroom reality, then we're all for it. But some of the borrowed bits keep the Crossfire out of the sports car Promised Land. Instead, the Crossfire finds itself at the crossroads between sports car and sporty coupe.