An upgrade in fuel economy without a downgrade in performance — that’s the goal for the 2012 BMW Z4 two-seat roadster.
And it’s the reason why the German manufacturer has replaced its base 3-liter, in-line six-cylinder engine with a turbocharged four-cylinder model. It is the first time in more than 10 years that BMW has put a car with less than six cylinders on sale in the United States.
The reasoning is easy to understand considering the tougher fuel consumption and emissions rules facing all carmakers.
The 2-liter, all-aluminum engine engine features a twin-scroll turbocharger and produces 240 horsepower and 260 pound-feet of torque. That compares with 255 horsepower and 220 pound-feet for the in-line six.
Most importantly, the four-banger should see a 20 percent improvement over the EPA estimate of 18 mpg city/28 mpg highway for the outgoing six-cylinder car. That would put it in the 21/32 mpg range.
And, importantly for enthusiasts, the new engine offers nearly identical performance (0-60 mph in about 5.5 seconds).
I had an all-too-brief encounter with the new Z4 — officially known as the Z4 sDrive 28i for reasons only the German manufacturer might be able to explain — during the annual Test Days held by the International Motor Press Assn.
My 20-mile route covered smooth and twisty two-lane macadam roads in the vicinity of the Monticello Motor Club about 90 miles north of New York City.
I will not pretend that I learned enough to make a conclusive assessment of the two-seater, but the first impression was a good one.
Anyone who knows about BMW vehicles can attest to the legendary smoothness and seamless power of its in-line six-cylinder engines, and any one of its cars so equipped is enjoyable to drive.
But, the Z4 is a sports car, and my instant reaction was that the four-banger actually seems more appropriate.
It’s a little bit coarser, especially at high engine speeds, but it also seems a little more involving. Despite its thoroughly modern construction, it recalled those oh-so-long-ago days when I cut my enthusiast eye teeth on British sports cars and watched them duke it out on airport runway racetracks.
Yes, I did wish for a little more of a racy sound coming from the exhaust system, but I’m guessing that was not the effect the German manufacturer was looking for in a high-end, $50,000 car.
The rest of this two-seater is pure BMW —excellent construction, comfortable seating, upscale interior, smooth six-speed manual transmission, precise steering, strong brakes, a slick folding metal roof.
Add to that an expertly tuned independent suspension, and you get a lively performer on the back roads and a comfortable cruiser on the highway.
On the down side, there is no room for storage behind the front bucket seats and there is precious little cargo space in the trunk when the metal roof is folded down.
The Z4 is only the first BMW to get the four-cylinder engine. The mid-size, 5 Series sedan will also have it as the base engine in the 2012 model year. In that comfortable sedan, buyers will no doubt be looking for quiet and smooth.
I’m not sure that the sophisticated two-seater I drove is ideally configured for nose-to-tail racing on the Monticello Motor Club race course, but the four-cylinder Z4 sure was an invigorating ride on the rural roads nearby.