Cadillac's two-seat XLR roadster has hardly set Mercedes-Benz aquiver with its sales success, but the high-performance XLR-V might have the chops to win a few sales away from the SL by offering SL55 AMG pace for loaded SL500 money. The dedicated XLR spotter may be able to discern the differences between stock and hot rod XLR, though the changes are pretty subtle: polished wire mesh upper and lower grilles; unique nineteen-inch, ten-spoke aluminum wheels; a hood bulge; and four stainless-steel exhaust tips. The XLR's interior--which hardly bears scrutiny against the SL or a {{{Maserati Spyder}}}--has been slicked up a bit with ebony wood, aluminum accents, and additional leather trim, but it's no SL55 AMG or upscale 911.
The XLR chassis is sharper than the SL500's, however, and Cadillac has enhanced it with a stiffer front anti-roll bar, the addition of a rear bar, and a sportier Magnetic Ride Control calibration. The brakes have been uprated, with bigger diameter 13.4-inch front and 13.0-inch rear cross-drilled rotors, a setup that is essentially the same as the Corvette Z51's. The StabiliTrak stability system now has four positions. The larger diameter wheels are accompanied by wider Pirelli run-flat 235/45 front and 255/40 rear tires.
The naturally aspirated XLR is hardly underpowered, with 300 hp and 310 lb-ft of torque, but the V's supercharged and intercooled 4.4-liter, 32-valve DOHC Northstar V-8 engine makes an exceedingly healthy 440 hp and 425 lb-ft-enough, says Cadillac, to push the V from 0-60 mph in less than five seconds. The engine is mated to a six-speed automatic transmission, the first time GM has used a six-speed auto in a rear-drive configuration. This features manu-matic control and GM's Performance Algorithm Shifting (PAS), which downshifts under high g cornering to ensure you don't hunt for a gear on corner exit.