2009 BMW M5 vs 2009 Cadillac CTS-V - Engine and Transmission - Comparison

Under their hoods, both M5 and CTS-V shiver with muscle, but here their recipes differ dramatically. The BMW's mill is the product of a Formula 1 clean room, a 5.0-liter V-10 fortified with a throttle body for each cylinder and an 8250-rpm redline -- enough for 100 horsepower per naturally aspirated liter (and 383 pound-feet of torque). The CTS-V will have none of that exotica. Its engine is, essentially, a "lite" version of the LS9 in the Corvette ZR1, though it's about the weightiest "lite" you'll ever see. Ahead of the firewall lie 6.2 supercharged liters of V-8, good for 556 horsepower and 551 pound-feet -- and possibly a nod to power the next Space Shuttle.

Though automatics are available with both sedans (the CTS-V's is a conventional six-speed slushbox with paddles, the M5's a seven-speed sequential manual), we ordered both test cars with six-speed manual boxes. The Caddy's manual shifter is the same Tremec TR-6060 used in the ZR1.

If the two sedans seem close on paper -- nearly the same size, the BMW less potent but the Caddy heavier -- at the track they proved even more so. With an aggressive clutch drop and all stability electronics turned off, the M5 stormed to 60 mph in just 4.1 seconds (the car might have been a tick quicker, but a rear sensor designed to protect the diff by monitoring wheelhop dulled the throttle for a blink). The CTS-V, by just 3800 rpm unleashing all 551 pound-feet upon the rear tires, required a more judicious foot at launch but managed an even quicker sprint to 60: just 4 seconds flat. That advantage extended only slightly in the quarter mile, the M5 running in 12.5 seconds at 115.3 mph, the CTS-V needing just 12.3 seconds at 117.0 mph. What the numbers don't reveal is just how heroic these sedans are in action, each one chirping the tires through third gear, the M5's exhaust a searing scream, the Cadillac's the deep, stentorian bellow of some almighty creature caged up on Olympus.

In our figure-eight test, the Caddy again edged its Bavarian target, circling in 25.2 seconds versus the M5's 25.8. After that, you'll practically need a microscope to tell the two apart: Both brake to a stop from 60 mph in only 109 feet, and maximum grip is nearly the same, 0.92 g for the Cadillac, 0.90 for the BMW.