2003 BMW Z4 3.0i

Sporting roadsters have long been an integral part of BMW's motoring heritage. From its original 315/1 to icons like the 328 and 507, these al fresco two-seaters helped establish the character of the marque by adding stylish sensuality to their underlying performance capabilities. With its new Z4, BMW has taken its boldest step ever in this genre. Determined not to produce a mere Mk II version of its Z3, the firm has totally recast its U.S.-built offering for '03. The result is a wholesale reinterpretation of the basic sports-car formula that melds classic proportions with a new look and new technology aimed squarely at the 21st century.

The Z4's distinctive mix of concave and convex contours gives it a unique "presence" that transcends mere sheetmetal specifics.

Visually, the Z4 is the first production BMW to embrace the "dynamic surfacing" philosophy seen on the radical X-Coupe concept car that was introduced at the North American International Auto Show in 2001. Although it shares the traditional proportioning of the Z3—a long hood and the driver seat set low and well back—the Z4's distinctive mix of concave and convex contours gives it a unique "presence" that transcends mere sheetmetal specifics. Punctuating this new flair are quad glassed-in headlamps—ellipsoid low beams and free-form highs, in conventional halogen or optional Xenon—as well as bolder rear lights that feature variable intensity "adaptive" braking illumination introduced on the new 7 Series.


Like its predecessor, the Z4 comes in two basic forms, the 2.5i that starts at $33,379 and the 3.0i, which opens at $40,945. Each carries a superb I-6 engine under its aluminum hood, the 2.5-liter making 184 horsepower and the 3.0 churning out 225. Both of these all-alloy twin-cammers are fortified with BMW's Double Vanos variable valve timing system that effectively optimizes output over the broadest possible rev range. While the engines carry over intact from the Z3, there are some significant changes in the transmission department. The Z4 2.5i retains the current standard 5-speed manual, but the 3.0i gets a new close-ratio 6-speed do-it-yourself box. Both also can be had with the optional Steptronic autoshifter that has a shift map custom-tailored to this application. The biggest news will hit in the spring, when a SMT (Sequential Manual Transmission) joins the Z4 option roster. While sharing the same basic lever-plus-paddles design as the SMT introduced in the M3, the Z4 version has fewer programs in both Auto and Manual modes. As for today's lineup, the Z4 3.0i with 6-speed will sprint to 60 mph in a claimed 5.9 seconds with the 2.5i/5-speed combo netting a still respectable 7.1 ticks. More than ample stopping power is supplied by 4-wheel ABS disc binders, vented/solid on the 2.5i, vented/vented on the 3.0i.

Although slightly more subtle in execution, the Z4's interior reflects the same flame-surface contouring found in its sheetmetal.

Beneath the Z4's dramatic bodywork lies an equally notable new understructure that boasts nearly triple the torsional stiffness of a Z3. Overall length rises modestly, from 159.4 to 161.2 inches. More important, the wheelbase moves from 96.3 to 98.2 inches, fore/aft track dimensions widen by 2.4/1.2 inches and the suspension geometry was tweaked at both ends for greater stability. Although BMW retained the Z3's strut-type front setup, the old angled trailing arm rear hardware has been jettisoned in favor of a multilink package culled from the current 3 Series. A host of aluminum components helps reduce weight while triangulating braces and thrust plates in both the front and rear do their part to keep all the chassis bits in proper alignment.


Rounding out the mix are gas-pressure shocks, front/rear anti-roll bars and a new compact and energy efficient Electric Power Steering unit that replaces the conventional hydraulic pump with a lightweight, fuel-efficient electric servomotor—and you have the makings of a thoroughbred backroad burner that weighs in just under or over 3,000 pounds (depending on powertrain and equipment). Both Z4s now wear run-flat tires that work in concert with an electronic tire-pressure monitoring system and eliminate the need for a conventional spare. The 2.5i wears 225/50VR16s on cast alloy wheels and offers 225/45WR17 RFTs as an option. The latter are standard fitment on the 3.0i, which can be further upgraded with a Sport Package that nets stiffer suspension components, a lower ride height and 225/40WR17 front and 255/35WR18 rear rubber.