Known for its fine wines, superb seafood and gorgeous coastline, Portugal is also one of the most dangerous countries for motoring. It's not so much the condition of the roads, most of which are good, but the utter lack of enforced speed laws and those who enforce them. If you needed an example of mobile anarchy, this beautiful country would do just fine.
It was somewhat surprising, then, that BMW chose the southern Portuguese town of Faro to unleash the latest iteration of its Z roadster line. This new drop-top sports a powerful inline six driving the rear wheels, and as if the locals weren't enough of a threat, light rain and slick asphalt had me envisioning spinning tires, jagged pirouettes and twisted metal.
I shouldn't have worried. After the first few corners, it became apparent the Z4 is an entirely new animal. The technology tucked beneath its sculpted flanks has given it capabilities far beyond the Z3's. It feels as tight as any coupe and hugs the pavement as though an invisible hand were guiding it through the turns. And that 3.0-liter motor--BMW should bottle the sound and the sensation. What a rush.
I'd spent many miles in european car's long-term Z3 a few years ago, enough time to feel how much was right with BMW's approach to a small roadster. Its 1.9-liter four-pot engine and aging E30-ish semi-trailing-arm suspension were great fun, though mainly because it was near impossible to overdrive the 140-bhp car. The Z3 eventually progressed into a far more involving roadster with bulging fenders and bigger motors, and the M version (and other six-cylinder Z3s) even came to demand respect, but the Z4 was touted to be a major step forward for the line.
With a certain amount of trepidation (keeping in mind Portugal's death rate per mile), I set out to explore the Z4's limits, which on paper appear to be very high. Add up a super stiff body/chassis, multi-link rear suspension, electronically assisted steering, DSC and, of course, a choice of powerful inline sixes, and how could it go wrong?
Well, there's the styling, a combination of convex and concour contours that should, like the new 7 Series, generate plenty of debate.
Still, the Z4's newness permeates every level of interaction between driver and drivetrain. The interior was subjected to a significant redesign that's strikingly modern in its understatement--long, sweeping expanses of leather, brushed aluminum or Sycamore wood lie flat along the dash face. The gauges are elegantly designed, like the dial of a fine watch, and feature various displays within the speedometer and tachometer.
From above, the cabin presents a pronounced "T" configuration, the wide dash panel framing the lighting switches, audio system and center air outlets. A navigation system (standard in the 3.0 and optional in the 2.5) is a distinctive element of the uncluttered design. Hidden within the top of the dash, it pops up on demand.
The new sport seats have prominent side bolsters, which help make them hugely supportive, yet they're relatively easy to get in and out of. Six-way manual or eight-way electronic adjustments are available. In typical BMW fashion, the pedals are arranged for those who heel-and-toe, and a nice new touch are pads within the footwells that help knees from bruising during spirited cornering. Like the new 7 Series, the Z4 is equipped with Active Knee Protection--two dedicated airbags positioned below the dash. Pack rats will be glad to hear the Z4's trunk is larger than the Z3's, both by design and from the absence of a spare tire. It'll swallow two golf bags or a weekend's worth of baggage.
The Z4 has a new softtop with a heated glass rear window and built-in tonneau cover. The pneumatically assisted top can be raised or lowered easily with one hand and locked into place, and it's a relief not having to fuss with a tonneau cover--the Z3's usually stayed in the garage, it was such a pain. The optional electric top is a simple one-touch affair--in a scant 10 sec. the roof disappears, replaced by 20 miles of headroom.
The cabin does have a somewhat Spartan feel to it. The Z3 had a distinctive, sporty look (lots of gauges and buttons), but the Z4 features the elegant, less-is-more appearance first seen on the Z8 roadster.
The Z4 rides on a totally reworked suspension. I quickly learned it behaves with exceptional poise and tenacity (more on this later). The front geometry is largely unchanged from the Z3, though the track is wider by a significant 60mm (2.4 in.). The Z3's strut-type arrangement was kept; no problem, it worked well. It was, though, modified with forged aluminum control arms and hollow strut rods to help reduce unsprung weight, and more caster was dialed in for better straight-line stability.
The rear suspension is essentially the same layout as the new 3 Series--a very good thing. Technically it's called a central link suspension and is comprised of a large, curved longitudinal arm pivoted directly ahead of the rear wheel's center point (hence the name). Each wheel also has an upper and lower lateral arm (wrought from aluminum) for a total of three links per wheel. The rear track was widened 29mm (1.2 in.) over the Z3's, and the suspension was calibrated with increased negative camber (2.25 at rest). That slight inward tilt to the driving tires is a visual clue this roadster's a serious player.
The chassis structure, too, was revamped to provide exceptional rigidity, its torsional rigidity almost on a par with BMW sedans. The Z4 has Y-form front longitudinal members, with each frame rail that carries the engine branching into a "Y" to form a side sill and half of the central tunnel. In this regard the architecture is like the Z8's. Like the M3, the body was reinforced with thrust plates--one in front is fashioned from aluminum and one out back is made of steel. Additional strength comes from the side sills and floor pan, fabricated from high-strength steel, which were also designed to spread the load from a collision over the largest possible area. Every Z4 will also sport an upper strut bar in the engine bay.
This suspension felt perfectly calibrated. The new standard suspension feels firmer than any sport-tuned Z3 I've ever driven, and the sport suspension...well, it was even sportier. It's by no means harsh, but it is incredibly firm, giving the impression that the Z4's engineers spent many, many days at the Nuerburgring trying to shave off a few tenths here and there.
Every Sport Package-equipped Z4 features Dynamic Driving Control, activated by a "Sport" button on the console. DDC dials in firmer steering effort, quicker accelerator response, and, in vehicles with the automatic transmission, more aggressive shifts.
Another new system for the Z4 is electronically assisted power steering. Rather than a standard hydraulic pump, the steering is assisted by an electric servomotor. This allows for specific steering tuning (shock damping, on-center feel, return to center, overall feel), speed-sensitive assist and reduced engine load. It works transparently, the steering feedback, as in most BMWs, near perfect.
The brakes were upgraded with larger rear rotors. The 2.5-liter cars get solid 11-in. discs all around, and the 3.0L Z4s are fitted with ventilated rear discs that are 11.6 in. in diameter. Standard running gear for the 2.5i measures 7x16 with 225/40R-16 rubber or 8x17 with 225/45R17 (2.5i Sport package; standard 3.0i). The full-tilt-boogie package for the 3.0i is a staggered setup comprised of 8x18s in front and 8.5x18s out back with front 225/40R18 and rear 255/35R18 tires. These wheels are all newly designed and appear more elegant than previous roadster fitments.
Two versions of BMW's M54 six-cylinder engine, either 2.5 or 3.0 liters large, are offered. These are right up there with the most refined inline sixes ever built, boasting impressive power and preternatural smoothness. Spin these motors to six grand, and you can build a house of cards on the aluminum hood. The 2.5 produces 184 bhp and 175 lb-ft of twist; the 3.0 makes 225 bhp and 214 lb-ft of torque. Although rated with the same output as previous iterations, these engines were modified (fine tuning of intake and new exhausts) for improved response at low to medium speeds. Gearboxes include a five-speed manual (standard in 2.5), five-speed Steptronic automatic (2.5 option, 3.0 option), six-speed manual (standard in 3.0) or the Sequential Manual Gearbox with paddle shifters affixed to the steering wheel (2.5 and 3.0 options).
Despite the rain, mud and Colin McRae wannabes crowding the roads, the new Z4 kept me out of trouble, behaving beautifully and sticking to the pavement as though it were magnetized. During one memorable corner, an oncoming gravel truck drifted wide while setting up for his next turn (that's the way they drive). There were two choices--become a hood ornament or try and pedal out of a collision. Either way, I was resigned to getting tagged on the rear quarter panel, maybe worse. A quick right turn and stab of the throttle caused the rear end to lose traction--for about a millisecond. The Z4 dug in hard, kicking up all sorts of muck and shot us forward, missing the truck by a few inches. My co-pilot and I were both silent for the next 20 minutes as the color returned to our faces.
"That traction control really works," observed Motor Trend's Dave Newhardt. A weak "yeah" was all I could manage.
We'd been saved by BMW's electronic safety squad--in this case it was the new Dynamic Traction Control (DTC) that decided reducing engine power would be counter to my desires. DTC offers enhanced traction under low-friction conditions, overriding BMW's Dynamic Stability Control (DSC), which operates via braking and reducing engine power. DTC is largely unobtrusive, a "driver's" traction control system, if you will. You don't know it's working until you really need it. Of course, it's possible to deactivate DSC and DTC, but that means a lot more work, if you're into that sort of thing.
The six-speed transmission in the 3.0i is sufficiently geared to tear up pavement in the first three gears. After that, the Z4 will rocket to an electronically limited 155 mph (146 mph for the 2.5i) and hit 60 mph in 5.9 sec. (7.1 for the 2.5i). And while both Z4 models are powerful, it's the way they use their muscle that makes them so exceptional. Shrink a Z8, and this is what you'd get. The MSRP for the 2.5i is $33,795 and $40,945 for the 3.0i.
Now, about that styling. Have you ever heard the line, "He/she has a great personality" before a blind date? It sets off warning bells, no? What are you being set up for? Usually it's something unusual. In the case of the Z4, it does have a stellar personality--smart, strong, athletic and hugely capable. But, it has a face only a designer could love. Perhaps I'm not "edgy" or "controversial" or "hip" enough to understand the Z4's design, but I don't. BMW designer Chris Bangle's explains it; I just don't get it. There will, however, likely be enough who do, and that's good. The Z4 is too good to leave at home on a date just because of its looks.