Track Tested: 2012 BMW Z4 sDrive28i

When we first drove the 2012 BMW Z4 sDrive28i, which carries BMW's first U.S.-spec four-cylinder power plant in 12 years, we said, "Our seat-of-the-pants impression tells us the Z4 with the turbo-4 has a significantly stronger midrange than the outgoing six." And our seat-of-the-pants view is supported by the on-paper specs provided by the new 2.0: 258 pound-feet of torque from 1,250-4,800 rpm and 240 horsepower at 5,000 rpm. Sure, that's some 15 fewer horsepower, but it arrives 1,600 rpm sooner and the torque is up by 38 pound-feet over the old I6.

What exactly does that mean for the Z4 sDrive28i when it's run full out? Follow the jump for our track data and impressions. And are those number enough to justify a $50,000 four-banger?

Vehicle: 2012 BMW Z4 sDrive28i

Odometer: 2,299
Date: 9-13-2011
Driver: Mike Monticello

Base Price: $49,525

Specifications:
Drive Type: Rear-wheel drive
Transmission Type: Six-speed manual
Engine Type: Turbocharged, direct-injected, inline-4, gasoline
Redline (rpm): 7,000
Horsepower (hp @ rpm): 240 @ 5,000
Torque (lb-ft @ rpm): 258 @ 1,250
Brake Type (front): 13.0-inch ventilated discs with single-piston sliding calipers
Brake Type (rear): 11.8-inch ventilated discs with single-piston sliding calipers
Suspension Type (front) Independent MacPherson struts, coil springs, driver-adjustable three-mode variable dampers, stabilizer bar
Suspension Type (rear): Independent multilink, coil springs, driver-adjustable three-mode variable dampers, stabilizer bar
Tire Size (front): 225/40R18 (88W)
Tire Size (rear): 255/35R18 (90W)
Tire Brand: Bridgestone
Tire Model: Potenza RE050A
Tire Type: Asymmetrical summer performance
As tested Curb Weight (lb): 3,225

Test Results:

Acceleration
0-30 (sec): 1.9 (2.6 w/TC on)
0-45 (sec): 3.9 (5.1 w/TC on)
0-60 (sec): 5.8 (7.0 w/TC on)
0-60 with 1-ft Rollout (sec): 5.6 (6.7 w/TC on)
0-75 (sec): 8.8 (10.8 w/TC on)
1/4-Mile (sec @ mph): 14.2 @ 97.2 (15.4 @ 91.8)

Braking:
30-0 (ft): 27
60-0 (ft): 103

Handling
Slalom (mph): 68.0 (67.3 w/TC on)
Skid Pad Lateral acceleration (g): 0.89 (0.89 w/TC on)

Db @ Idle: 43.7
Db @ Full Throttle: 76.8
Db @ 70 mph Cruise: 66.8

Acceleration:Sport Plus mode doesn't allow revs to rise above 3,000 rpm at launch. Used Sport with DSC off and launched around 6,000. Get some initial wheelspin, then bites with a bit of axle hop, then full traction. Shifter is slightly notchy and balky for the 1-2 but smooth for 2-3. Momentary power bog when popping the clutch with each upshift. Good pedal placement for heel-and-toe downshifting.

Braking: Crazy-short stopping distances. First stop was 106 feet, best was 5th stop at 103. Ultra-firm pedal, short travel and no side-to-side wiggle. Grippy tires. Shortest stop came in Sport Plus mode, pretty much zero nosedive.

Handling:

Skid pad: Lots of grip, hardly any body roll. The Z4's driver-on-the-rear-axle seating position makes it more difficult than most cars to see over its long nose to stay on the arc. Also, touchy throttle makes smooth inputs a challenge. ESC system hardly felt, adds just a bit of brakes if there's too much understeer when in Sport Plus.

Slalom: ESC-off runs in Sport mode, ESC-on runs in Sport Plus, as ESC cannot be fully defeated in Sport Plus. Quick steering that's precise, but offers little in the way of feel. Suspension, too, isn't great about delivering feedback to the driver and tires are very quiet. Have to trust the grip, of which there's a lot. Nice thick-rimmed steering wheel. ESC is very hands-off even when switched on, but upsets the car's attitude a bit when it adds brakes.