My Experience
I've always been fascinated with minimalist, two-seat roadsters. This affection started when I came
thaaat close to buying a '74 Triumph Spitfire in high school, and became deeply entrenched after owning a '95 Miata in college. Combining light weight, low build, and an open-air cockpit, I've found that a good roadster offers the purest form of driving pleasure available.
With this bias in mind, you can imagine how excited I was to hear about BMW's Ultimate Drive event, which allowed attendees to take the company's Z4 roadster--among other vehicles--along a fast, twisty route of mountain roads. After driving three Z4s, though, I walked away feeling not desire, but disappointment. It was the first time I'd exited a roadster with my "want-it" bug happily dormant. Where did the Z4 go wrong? And will other buyers share my indifference?
Performance
The Z4 offers a choice of engines familiar to any BMW fan: a base 184-horsepower 2.5-liter Six, and an optional 225-horsepower 3.0-liter Six. Both saw duty in the popular previous-generation 3-Series sedan.
Eager to experience the Z4 in its sportiest form, I drove the 3.0i version first. So equipped, the Z4 feels plenty strong indeed. As in its other applications, the big Six endows the Z4 with a wonderfully linear, broad-shouldered powerband. Simply flatten the accelerator--anywhere on the tach--and a swell of torque flings the car effortlessly forward.
This engine's linearity is a double-edged sword, however. Since the power comes on in such a predictable fashion, the 3.0i needs every last ounce of its thrust to be exciting. There's no perceived "peak" or "rush" during hard acceleration, so once you've acclimated to the big numbers rolling up on the speedo, full-throttle runs ultimately aren't that thrilling.
It was primarily for this reason that I preferred driving the smaller-engined Z4. On paper, the 2.5i looks
way down on power, but on the road, the sensation of speed is quite similar. There's less grunt down low in the rev range, so takeoffs aren't quite as muscular. But the 2.5i's "sweet spot" around 4000rpm makes up for it, encouraging you to get involved and shift accordingly. In comparison, the 3.0i's flat-as-a-board powerband seems a bit characterless.
Perhaps realizing that this could be an issue, BMW has taken pains to give the Z4 a sporty, rorty exhaust note. They've even installed a plastic resonating chamber under the hood to make sure that the engine is sufficiently loud. However, "loud" doesn't necessarily mean "musical"--just ask Nickelback--and the Z4's indistinct baritone blat is uncharacteristically boomy for a BMW. Otherwise, refinement is quite good. Both Sixes rev with silky smoothness, and both lower their voices politely in light-throttle cruising.
Transmission/Clutch
I've found myself underwhelmed by BMW's manual transmissions in the past, but the Z4's is the best of any Bimmer I've sampled to date. The Z4's shifter isn't as snappy or millimeter-precise as a Honda S2000's--and maybe not even a 350Z's--but the lever's crisp, chunky feel and short throws are still quite satisfying. Clutch travel is pleasantly short, too, although take-up remains numb due to the marque's usual highly-insulated pedals.
I also sampled the Z4 with the optional automatic transmission, but I wouldn't advise potential buyers to do the same. The GM-supplied slushbox robs the Z4's powertrain of immediacy, delaying throttle response and making tip-in feel lazy at low speeds. Some of this tardiness can be exorcised by slipping the lever into "Sport," in which low gears are held longer. But this mode also locks out fifth gear, and that makes for unnecessarily revvy progress on the freeway.
A third transmission choice is BMW's SMT, which is essentially a manual transmission with an automated clutch. I didn't drive a Z4 so equipped, but professional reviewers have panned this setup repeatedly. It's said to be far jerkier than a well-driven manual, which rather defeats the point unless you're intrigued by the technology.
Steering/Handling
This was the area in which the Z4 let me down the most, because it's not fun on the sort of roads where a roadster should be. The reason for this shortcoming? Well, it seems BMW prioritized good skidpad numbers over good seat-of-the-pants enjoyment--the Z4 will grip and grip, but doesn't let you play with anything more than a bit of front-end scrub. When I stabbed the gas to try and rotate the Z4's tail, its DSC simply throttled back the engine and let understeer grind away the car's momentum. A Mazda Miata, by comparison, lets you play its chassis like a musical instrument.
The Z4's electrically-assisted steering is another weak point, failing to meet BMW's usual standards of precision and feedback. It feels meaty and accurate once you've dialed in a quarter-turn of lock, but around the straight-ahead, the helm feels disappointingly fuzzy and inert. Small inputs seldom have the desired effect, and the wheelrim feels numb to surface vibrations. The optional Dynamic Driving Control's "Sport" setting adds a touch more heft, but no more accuracy. In truth, you'll get better path control from an X3 or X5.
So, thus far we've got a chassis that's slightly too sticky for its own good, and steering that lags behind the class best. Not the end of the world, right? Well, unfortunately, it gets worse. Up until now, I've only described the Z4's handling on
smooth surfaces. Where the Z4 really falls apart is on bumpy, twisty back roads--in other words, exactly the kind of route where you'd expect a two-seater to shine.
Tearing through the patchy mountain roads that BMW chose as a test loop, there was only one car in the company's lineup that gave me white knuckles--and it wasn't one of their SUVs, but the Z4. Even on the straight sections, the Z4 darted and fidgeted from side to side, the tires tramlining in the road's lumpy topography as the steering wheel kicked in my hands. The steering's on-center feel became even looser over the bumps, too, so I found myself fussing busily with the wheel to maintain a straight course. I'll say this for it: it wasn't boring.
Of course, I realize that what's spooky to one driver can be sublime to another. But the universal problem with the Z4's handling is its lack of consistency. If you're into the Z4's "retro" rough-road reactions, it'll bore you to tears on fresh asphalt. And if you like the car's safe, benign handling on good roads, it'll terrify you when the pavement deteriorates.
Ride
As you've surely guessed, the Z4's ride characteristics fall right in line with its handling. Its well-damped firmness is exquisite on smooth surfaces, but progress becomes seriously stiff and crashy over the bumps. Sharp impacts can send quick judders through the Z4's structure, too--a trait I found rather disappointing in a BMW, even if it
is less pronounced than in most open cars.
Given the Z4's Jekyll-and-Hyde ride comfort, I seriously doubt that many buyers will want to shell out $1,200 for the optional Sport Package. It includes larger wheels, lower-profile tires, slightly stiffer suspension settings, and the aforementioned Dynamic Driving Control, and while none of this degrades the ride significantly, it doesn't improve the car's handling, either. If you just want the package's stylish alloys, they're available individually as dealer-installed accessories.
Interior
Finally, here's an area where I can drop the negativity and start giving the Z4 some compliments. And ironically, it isn't the work of BMW's chassis engineers that I liked, but of their much-maligned design director, Chris Bangle. Although many professional reviewers have taken issue with the otherwordly angles and arcs that make up the Z4's interior styling, I love the overall effect. Its slightly alien aesthetic seems appropriate, given BMW's not-quite-explainable reputation for excellence.
The Z4's interior also fares well in terms of substance. Panel fits are excellent, and while most surfaces feel hard and spare to the touch, this is in line with the car's Teutonic character. There's enough clever detailing and tactile variety to keep the hands entertained, too--I especially liked the padded handbrake surround that ingeniously doubles as an armrest. My only complaint centered on the strip of rough, grainy "brushed" aluminum spanning the dashboard. What, exactly, did they brush it with? A hatchet?
Function is just as important as form in a sporting car, of course, and I was generally pleased with the Z4's cabin layout. The low driving position is spot-on, affording a splendid view of the sweeping hoodline. The wheel-pedal-shifter relationships are ideal, too. The standard "sport" seats are too flat to provide much lateral support, but they're remarkably comfortable for this sort of car. Even the secondary controls are well-placed--the radio is mounted nearly parallel with the gauge cluster.
The Z4 does stumble in one important aspect of ergonomics, however, and that's outward visibility. In a clear case of style dictating substance, BMW chose an "oval" theme for the car's mirrors--the tiny wing mirrors offer little blind-spot coverage, while the curved rearview unit cuts off the bottom edges of the picture. The resulting need for rubbernecking could very well break the deal for some.
Practicality
You wouldn't be considering a roadster if you were deeply concerned with practicality, of course. But it never hurts to have a little extra space, and here the Z4 delivers a couple of pleasant surprises. Its trunk isn't particularly well-shaped, but it displaces 9.5 cubic feet--just a bit more than a Kia Rio sedan's. The Mazda Miata and Honda S2000, for comparison, offer about half as much space for luggage.
The Z4 also features more interior storage than its rivals. There's a reasonably-sized glove compartment, wide door pockets, a couple useful center-console bins, and a net on the right side of the drivetrain tunnel. As two-seaters go, this is pretty posh stuff.
Reliability
Unlike the British roadsters of previous generations, today's two-seaters don't require you to be on a first-name basis with the owners of obscure repair shops. The Miata and S2000, in particular, have earned quite enviable reputations with the leading consumer advocacy magazine. The Z4 does pretty well, too--it scored an Average rating in the same publication's reliability surveys. But bear in mind, if anything does go wrong, BMW's parts and service rates amount to highway robbery when compared to those of the Japanese brands.
Overall
I consider it a bad sign when it's unclear what kind of buyer a new car is targeting. The Z4, unfortunately, is one such machine. Its split personality goes hand-in-hand with the reason it didn't push my usual roadster buttons--it lacks a sense of mechanical focus.
Is the Z4 a hardcore sportster, along the same lines as Honda's S2000? It's tempting to pin it as such--it's fast, no doubt about that, and its grippy tires and jolting ride sound like real track-day stuff. Taken as a whole, however, the Z4's vague steering and concessions to refinement place it well short of the mark set by more dedicated roadsters.
So, does that make the Z4 a two-seat grand tourer? Perhaps... but no, that's not right either. What grand tourer shakes its occupants mercilessly over bumps, or becomes nerve-wrackingly twitchy on neglected mountain passes? What the Z4
really is, I think, is a roadster with a poorly-judged sense of balance--and Mazda will be happy to sell you a Miata, with balance galore, for $10,000 less than the Z4's base price.
That said, I imagine that little of this will matter to people who end up buying Z4s. That's because, while many people love roadsters for their speed and agility, there are at least as many who simply like the way they look. I personally find it difficult to forgive the Z4's mechanical inconsistencies, since my evaluations are primarily drawn from the driving experience. But with its combination of striking looks and badge prestige, The Z4 is sure to excel at turning heads and impressing valets. And if no one was interested in vehicles with these priorities, well, there would be no such thing as an automatic-transmission Porsche.
Feel free to check out my reviews of some of the Z4's competitors:
Mazda MX-5 Miata
MINI Cooper S Convertible
CarsBelowInvoic e
