Z4: The Zen of auto experiences

Twice during my recent weeklong test of the BMW Z4 Roadster, passengers were moved to comment without provocation, “What a nice car.”

The Z4, which has been significantly upgraded for 2006, had a lot going for it that week: beautiful weather, agreeable riders, and a relaxed schedule that allowed for plenty of road time.

And it was gracious enough to honor its end of the bargain.

There are two Z4 models for 2006: the Z4 Roadster 3.0i (from $36,295, including destination) and Z4 Roadster 3.0si ($42,795). They are more powerful than last year’s models and get a mild facelift, stronger brakes, larger wheels and tires and an improved electronic stability control system.

They’re the first (non-M) roadsters based on the 3-series platform to offer performance on a par with the sport sedans for which BMW is justly famous. Still, I’m not sure what prompted my guests’ unbidden enthusiasm — even they couldn’t put a finger on it — but here are some guesses.

There is, of course, the obvious pleasure of driving an open-top car on a perfect, late-summer day.

But, more than that, perhaps it was the seats that thrilled them. Our tester wore the optional M Sport seats, which are worth every penny of the $500 they command. They are firm and supportive and their side and hip bolsters nudge gently but purposively against the torso, containing it during spirited driving.

Maybe they were responding to the Z4’s attractively designed interior, the quality and feel of the materials, the way the switchgear fell easily to hand and responded firmly and precisely to the touch.

Or it may have been the quality of the ride. Our tester was equipped with the $1,000 Sport Package, which included staggered-width 17-inch alloy wheels and a sport-tuned suspension. Some say it’s too firm, but I find it “just-right” in that Goldilocks sort of way. Paired with the Z4’s extremely rigid body shell, the suspension produces slot-car handling without the teeth-rattling harshness of some performance cars.

You will know when you cross a set of railroad tracks, but you won’t feel abused.

The Sport Package also includes a feature called “dynamic driving control,” which at the push of a button speeds throttle response and reduces power-steering assist. It may not have done much for my passengers, but it made my day.

My charges may have been basking in the reflected-glamour phenomenon, which makes it darn near impossible to feel unattractive in the Z4.

When it was introduced in 2003, the Z4 was widely criticized for its odd assortment of angles, edges and curves. But the look has worn well, aided this year by updates that include larger front air intakes, new front side reflectors, new wheel designs, new taillights and rear bumper and a new palette of metallic colors.

Three years down the road, the Z4 still looks contemporary and fresh. Drive around town, top down, and you will be noticed, though not in an ostentatious, show-offy way (although the fellow eating at Dick’s who loudly derided us across two lanes of traffic as yuppie scum and suggested we go back to Idaho [!] would disagree).

My friends might also have been responding to the lovely sounds the Z4 makes. Both engines use the same 3.0-liter, inline, six-cylinder architecture with variable valve timing, although that doesn’t come close to describing the trick stuff that make this pair among the world’s best.

The 3.0si is the bulldog of the two, but both pull with great strength across a wide power band.

That strength is expressed in a beautifully tuned exhaust note. Slip from third gear to second to round a corner, put your foot back into it, and the dual pipes sing a sweet and seductive song. A firmer foot on the throttle coaxes from the engine compartment an exhilarating mechanical aria.

For 2007, the automatic and manual transmissions on both models get six gears. The automatic has a sport mode and can also be shifted manually, via steering wheel-mounted paddles. The stick is a smooth-shifting, short-throw unit with well-defined gates. The one in our tester was clearly superior to that of the 330i sedan we drove recently.

The improved stability control system includes Brake Drying, which does what it says; Start-off Assist, which holds the car in place when starting on a hill; and Brake Standby, which readies the brakes for action if the driver’s foot lifts abruptly from the gas pedal.

Ninety percent of the time, all this brilliance is mere background to the daily routine of clutch/shift/steer, which BMW executes better than anyone else on the planet. But then there are those moments of transcendence — something as simple as coming out of a corner downtown — when the exhaust note alone is enough to focus your mind on the here and now and remind you you’re driving something special.

It’s the Zen of automotive experiences. And, while the passenger’s experience is doubtless less gratifying, it should be obvious that it, too, has its rewards.

Nice car indeed.