Tested: Five 2006 $100K Convertibles Vie for Hearts and Wallets

From the Archive: Chasing sunsets and driving enjoyment with the drop-top 2006 BMW 650i, Cadillac XLR-V, Jaguar XK, Mercedes SL550, and Porsche 911.

It’s spring at last, the Dow is flip-flopping, and—if you’re in the right bracket and the damn market goes back up—the Bushies will be giving you just about enough of a tax cut to buy an expensive convertible. For sure, there’s nothing like a shiny new convertible to scoop up the joys of spring and blow ’em right into your face. And we have some pretty blossoms in the bunch this year.

For one, the new Jaguar XK convertible, with an all-aluminum body, is now light enough in naturally aspirated form to run within a half-second of the previous generation’s supercharged version. Launched close to the debut of its coupe equivalent, the XK convertible benefits from having been a part of the original engineering job. Which means it’s inherently stiff and sturdy by design—Jaguar says 50 percent more so than its predecessor, which was known for shivering and shuddering its way across rough surfaces.

The new XK convertible is powered by a 300-hp, 4.2-liter V-8 via a six-speed ZF transmission with a specially massaged manumatic system for super-fast shifts. Traction control, dynamic stability control, and Jaguar’s CATS variable-damping shock-absorber control are standard. The fabric convertible top is fully automatic, able to stow itself in about 18 seconds, and as we’ve become accustomed in Jaguars, the interior is a welcoming blend of burl veneer and soft leather.

Even more welcoming—particularly in this expensive grouping of convertibles—is the XK’s as-tested price of $85,200. That makes it the least expensive bloom in the bunch.

Further along the price spectrum is another recent addition to the convertible clutch. It is Cadillac’s $100,000 XLR-V, powered by General Motors’s supercharged Northstar V-8. This blown four-cam jewel produces 443 horsepower and 414 pound-feet of torque, with 90 percent of that torque on tap between 2200 and 6000 rpm.

Accompanying the big power boost is a full round of suspension and equipment upgrades over the standard XLR, including larger brakes, recalibrated Magnetic Ride Control, the addition of a rear anti-roll bar, unique badging, polished stainless-steel exhaust tips, and special wood and leather interior surfaces. But what makes it eligible for this particular spring-break bash is its fully automatic retractable hardtop, bringing coupe-like insulation and refinement to the droptop realm.

Targas aside, Porsche’s 911 has had a full convertible version in the lineup since 1983, and this is true of the latest-generation 997 models, too. For this test we ended up with a 3.6-liter Carrera model in order to have automatic transmissions in all the cars. It is possible to specify the more-powerful Carrera S cabriolet at less than $100,000 and stay within our budget for these cars, but Porsche couldn’t supply one with an automatic.

What might have happened to the rankings had we tested the 3.8-liter Carrera S will have to remain the subject of conjecture, but we have to say that the 325-hp Carrera seemed to us a nicely balanced vehicle, even if that figure represented the second-lowest power output of the group.

No droptop shakedown would be complete without a Mercedes-Benz SL. After all, an SL hardtop convertible won a similar contest in our October 2003 issue against three of the brands you see here, and it has since benefited from a face lift and an important engine transplant. The SL550 debuted at the Geneva auto show earlier this year with a freshened face and a new-generation four-valve 5.5-liter V-8 punching out a respectable 382 horses. With a long-running reputation for astonishing stickers, the Benz SL clocked in at a dizzying $102,375. We’ll see if it’s worth it.

If there’s a Mercedes in the mix, there has to be a BMW nearby, and the 650i brings a 4.8-liter V-8 to the party for 2006, producing 360 horsepower, 35 more than the preceding 645Ci, and with 30 more pound-feet of torque. New wheels distinguish the car from last year’s model, and the active steering feature that troubled many of us has been dropped from the optional Sport package and is now available as a standalone item.

Despite boasting the lowest base price in the group, the 650i wore a $1000 head-up display among its optional extras (the Cadillac has one, too, included in its price) and a stunningly pricey active cruise-control system ($2200) that helped bump the sticker to $87,640. As tested, only the Jag was cheaper, if that’s the right word here. Playing in this league is clearly the privilege of the well-heeled.

Fifth Place: Cadillac XLR-V

Our five testers agreed that the XLR-V made a much better everyday driver than the Corvette with which it shares its basic structural architecture. With a smoother, adaptable ride, an intelligent automatic transmission, and relatively easy ingress, we could see ourselves commuting in this car with little discomfort. The retractable hardtop adds considerable utility, too, providing a quiet and insulated environment for when you need to avoid that wind-in-the-hair experience.

Highs: Refinement, performance, versatility.

But that’s not saying much. For $100,000, one expects some razzle-dazzle beyond the role of everyday driver, and you certainly get some of this with the XLR-V. The sheer ferocity of its supercharged V-8 is definitely on the sensational side of the thrill ledger. Easily the quickest car here, the XLR-V rips off sub-five-second sprints to 60 mph and 13-second quarters. Not bad from a car with an automatic transmission.

That it can do that and then resume a smooth and tranquil freeway cruise is one of the XLR-V’s strong suits. But the car is not without its downsides. Not everyone likes the flat planes and sharp creases of its bodywork, or the aggressive leer of its wire-mesh grille. Two of the five test drivers are more than six feet tall and found the interior accommodations on the tight side. The seat was criticized by one tester as being firm under the butt but squishy under the thighs—“like a very shallow water bed,” he wrote.

Despite the Bulgari involvement indicated by its logo, the cockpit itself isn’t particularly warm and inviting. The vertical console and the angular moldings are tidy and symmetrical but lack the complexity and subtlety required for long-term aesthetic appreciation. Several testers commented on the overlarge steering wheel, and some complained about a primitive gear-selector feel. We’d like to see steering-wheel buttons or paddles for the manumatic control, too.

Although the XLR-V is undeniably fast out on the roads of the sports-car world, with one of the best stability-control systems in the business, Cadillac’s efforts to retain a modicum of civility have clearly blunted the car’s communications skills. It just isn’t transmitting the whole performance picture to the driver through the wheel and seat. Other than the unequivocal engine response at full throttle and an occasional vibration through the steering wheel and rear suspension when encountering rough spots, the car is somewhat numb.

With smaller tire footprints than its bow-tie brother, the XLR-V was prone to some lurid slides while negotiating our lane-change test with the StabiliTrak system turned off. This tail-happy conduct is surprising in light of the car’s nearly equal weight distribution, but it’s mitigated by the brilliant dynamics provided by StabiliTrak in full control, which allowed the car to negotiate the lane change at the second-fastest speed in the group.

It is largely in the arena of tactile quality that the XLR-V disappoints. The Magna-Steer variable-assist steering remains relatively dead in your hands. The Caddy takes the longest distance to stop from 70 mph, and the brake pedal is pretty wooden underfoot. And although the six-speed transmission is located in the right place for weight distribution—just ahead of the rear axle—and is equipped with all the most up-to-date components and electronics, it was often tardy in dishing up a downshift.

The Verdict: A good choice if you must be seen in a domestic vehicle.

Lest readers think this is just a litany of complaint, it must be remembered that the XLR-V will appeal strongly to drivers whose tastes and intentions are in keeping with its strong suits. This is a fast, striking, well-equipped car with the big advantage of a hardtop convertible. Without its peers to spotlight its various shortcomings, this car would be considered highly desirable. With that in mind, it was mostly the high price that confined the Cadillac to fifth place.

2006 Cadillac XLR-V
443-hp V-8, 6-speed automatic, 3860 lb
Base/as-tested price: $100,000/$100,000
60 mph: 4.6 sec
100 mph: 11.0 sec
1/4 mile: 13.0 @ 109 mph
Braking, 70–0 mph: 173 ft
Roadholding, 300-ft-dia skidpad: 0.83 g
C/D observed fuel economy: 14 mpg

Fourth Place: BMW 650i

The 650i convertible is the product of an intensive development exercise intended to produce unprecedented levels of refinement, and it’s as sophisticated in that regard as the best of the Lexuses. Unfortunately, the painstaking effort expended in the search for seamless luxury seems to have eradicated many aspects of the BMW character that we and so many Bimmerphiles admire.

Highs: Great engine, usable four-seat space, rich demeanor.

BMW’s press kit tells us the body of the convertible—with its various reinforcements and gussets—is slightly stiffer than the 650i coupe before glass is added. (The coupe is stiffer with all its glass in place.) Yet here’s what the C/D logbook says: “Noticeable cowl shake over rough stretches. Doesn’t feel as solid as most of the others.”

But the fact of the matter is that the 650i is extraordinarily quiet, stable, and supple in its everyday dealings. That cowl shake was probably the only noticeable manifestation at the time. The BMW recorded the lowest decibel readings in the three sound categories we measure. It never felt as if it were doing anything dramatic, but it pulled the second-highest lateral-acceleration number in the group. And its last-place finish in the lane-change test probably had more to do with the dearth of chassis feedback than anything else.

Let’s be charitable and call this car subtle. Extremely subtle, requiring a longer relationship with its owner than a half-hour in the seat between car swaps on a test drive. Then we might come to terms with an exhaust note so quiet it’s soon dispelled by wind noise. A broad spread of torque from the 4.8-liter V-8 means the car isn’t constantly shifting gears. That’s a good thing because the kickdown isn’t notably responsive in the 650i.

And let’s say we don’t want constant info from the chassis disturbing our relaxed grip on the utterly becalmed steering wheel. Don’t worry, there isn’t really much of that. Still, on the other side of the wall of isolation is a well-engineered car going about its business. It’s just that much of it is evidently none of our business. This car is so inert there’s not a lot to be gained from reading the drivers’ logbooks.

Lows: Anesthetic isolation, a heavyweight, controversial styling, bland personality.

Yet the BMW is loaded with high-tech gadgets, and not all of them are associated with the annoying iDrive mechanism (which gets a little soft pad on its control knob this year, in case you care). The automatic softtop—it was not universally considered handsome—raises in about 25 seconds, draping itself over five windows in the process.

The short, vertical rear glass can be left in its upright position to act as a draft excluder for the rear-seat passengers. The BMW was best in this group at transporting rear-seat passengers (the Benz and the Cadillac have no rear seat at all), but not behind the two six-foot-something testers on this trip. Their seating positions had the front backrest firmly in contact with the rear cushion.

If the BMW is about cruising, then it has all the cards: a great stereo, a navigation system, automatic climate control, stability control, and a host of special brake-related programs from wet-weather clearing strategies to something called comfort stop, which alleviates that sudden snap stop practiced by bad drivers. For fast, daylong cruising, the 650i is in a league of its own. Want to do 1000 miles today? Go right ahead.

But it feels a tad heavy on California’s goat tracks, even if it negotiates them gracefully. We had reports of unexpected understeer from one driver and sudden snap oversteer from another. It’s probably their own fault for misinterpreting the corners, but a lack of immediacy and clarity in the car’s controls is undoubtedly a co-conspirator.

The Verdict: Super luxurious, but the victim of a BMW-ectomy.

Adding to the team’s doubts about the 650i’s sporting credentials was a singular concern over its appearance. We thought it odd-looking with the top down and arguably ugly with the finned top up. All things considered, the BMW 650i is lucky it didn’t finish fifth.

2006 BMW 650i
360-hp V-8, 6-speed automatic, 4300 lb
Base/as-tested price: $79,495/$87,640
60 mph: 5.5 sec
100 mph: 13.4 sec
1/4 mile: 14.0 @ 102 mph
Braking, 70­–0 mph: 161 ft
Roadholding, 300-ft-dia skidpad: 0.91 g
C/D observed fuel economy: 15 mpg

Third Place: Jaguar XK

This new XK convertible is an easy car to underestimate. At first acquaintance it seems docile, mellow, and not at all likely to get in your face. Also hard to forget is that at 300 horsepower the XK is the least powerful car in this test. In the first few minutes after you start the car and drive off, the impression of a mellow and quiet grand tourer is reinforced by a pliant ride, smooth automatic upshifts, a nicely weighted but calm steering wheel, and seats that seem too softly padded for aggressive driving.

Highs: Stable chassis, amazing ride-and-handling compromise, responsive transmission.

Then, as the miles pile on and the pace picks up, the XK seems to amp up its feedback until, at crazy speed—when you’re braking hard into a turn, tugging on the paddles, and hearing the dual exhausts bark their baritone song as the computer matches revs—driver and car are suddenly dancing in precise rhythm.

That happened once we’d taken to the hills, but first there were some surprises at the test track.

After declaring the car “a cruiser” in his first logbook notes, tech editor VanderWerp found himself surprised by the car’s good acceleration, despite its not having substantially more power than previous Jags. “The weight loss and the quick-shifting tranny must help a lot,” he wrote. Then we moved to the lane-change exercise, where the XK cut effortlessly through the cones. We held down the stability-control button, as instructed, to raise the intervention threshold and could detect no more than one brief brake application to settle the car during runs that were more than 2 mph better than the second-quickest car.

Out in the hills the XK continued to impress. The car tackles the twisties with real poise yet never seems to stiffen its ride or responses to the point of severity. The paddle-directed fast upshifts and blipped-throttle downshifts lend real sporting character, and on several occasions we found ourselves drawing to a stop and pulling on both paddles to find neutral, the way it’s done in Ferraris and Lamborghinis. That’s how authentic the experience is.

Lows: Poor softtop fit, some electronic glitches.

The XK provides plenty of room in the front seats, even if full deployment of available space negates the whole idea of rear seating. The word occasional hardly covers it, but at least those rear seats—however vestigial—provide extra luggage space for folks who like to travel with the top down. (The Caddy has a bulkhead directly behind the front seats; the Mercedes has a small parcel shelf.)

Like the other cars in this test, the XK’s top motors automatically into its own bin and is then tidily covered by a panel that integrates neatly with the car’s body. There is no draft-deflecting apparatus on the Jag, but wind-flow management is good, and the car can be driven comfortably with all the windows down. And once you’ve heard the V-8 trumpet during downshifts in the canyons, you’ll only put the top up when it rains.

The more cynical among us took issue with the inevitable burl veneer and leather interior, accusing Jaguar of resorting to its clichéd image when designing the cabin. For customers who feel the same way, there is a brushed alloy treatment that banishes any sight of timber. But for people who like the Jaguar look, the leather and the wood have been carefully crafted.

The controls are easy to find and operate, too, although the same cynic complained about the new touch-screen information and navigation display, saying the buttons were small and hard to operate and it took long periods of staring to get what you want. Perhaps this is why many manufacturers prevent use of the nav display with the car in motion, Robinson.

There were a couple of concerns about quality. Along with some unexplained warning-light illuminations, we noticed incomplete weather sealing on the XK’s top. A gap on the passenger side produced whistling noises at speed and allowed a trickle of water through during our car-wash test.

The Verdict: An impressive new Jaguar.

We hope all XKs don’t suffer this problem, because this is a good car, and it deserves to do well.

2006 Jaguar XK

300-hp V-8, 6-speed automatic, 3880 lb
Base/as-tested price: $81,500/$85,200
60 mph: 6.0 sec
100 mph: 15.3 sec
1/4 mile: 14.7 @ 98 mph
Braking, 70­–0 mph: 163 ft
Roadholding, 300-ft-dia skidpad: 0.87 g
C/D observed fuel economy: 16 mpg

Second Place: Porsche 911 Carrera

My, how things have changed. In bygone times Porsche’s 911 would be the hot rod in almost any comparison with similarly priced rivals. In this group, only the aluminum-bodied XK has fewer steeds in harness. But power isn’t the measure of overall vehicle excellence. Sometimes balance plays an equally important part.

Highs: Sporty character, intimate driving position, fast top operation.

The 911 Carrera we drove in this comparison disappointed at first, mainly because of the way its five-speed Tiptronic transmission seemed to soften and sap the car’s power delivery, particularly when making second-gear starts, as it often does. With an exhaust note considerably milder than what we recall from 911 cabriolets of the past, the overall impression was of a cream-puff convertible aimed at affluent metronauts.

At the drag strip, the 911’s 325-hp flat-six produced results that put it slap in the middle of this group, with zero-to-60-mph and quarter-mile times that were exactly average. But with the lane-change test came an attitude change. Even with the car’s stability-management system switched off, the 911 negotiated the course with remarkable composure.

It seems the 997-series cars have made meaningful improvements to chassis performance. The 996-series 911 Turbo S cabrio we tested just a year ago in August was downright scary in the lane-change test, even with an all-wheel-drive system. This newfound balance in the latest car translated to big fun in the mountains, too, where the famous 911 car-to-driver relationship reemerged in full color. By using the steering-wheel-mounted manumatic control buttons, we could eliminate some of the automatic’s “gooey” reactions (as described by one tester) and highlight the car’s dynamic responses.

“Definitely the sports car in the bunch,” noted one of our test drivers, who then added, “Excellent driving position with a commanding view of the road ahead.” Nonetheless, this did not blind us to some evidence of steering-column shimmy and cowl shake when the roads got bumpy, or to the fact that the tautly suspended 911 hops and bounds when traversing rough ground at high speed and produces rubbing noises from the left front wheel in hard right turns. Still, as they say, there can be no speed without control.

Lows: Sluggish transmission, bouncy handling, just-adequate power.

The best thing about the 911 cabrio is its organic nature, its ability to commune with its driver. It doesn’t hurt that the rear-engine format is highly unusual among orthodox designs, setting the car apart from the norm. Or that all mechanical noises come from back there somewhere and are at close range when the top is down.

Since driving open-top cars at very high speed isn’t all that enjoyable or confidence-inspiring, charm is a big part of the segment’s allure. This the Porsche has, and it steadily seduced our team into writing warmer and warmer logbook comments and ultimately onto ballots that lofted it into second place.

Some of our motor noters expressed appreciation for aspects done simply but well. The top, for example, operates faster than all the elaborate devices on the other cars. Although it has a motorized panel at the rear of the roof to secure its trailing edge, that panel doesn’t form a boot in the way it’s done on the other cars. The roof itself forms a tidily contoured part of the boot when the top’s down. This arrangement retains the legendary 911 mini–back seats despite a beefy aluminum bulkhead added to house the dual pop-up roll-protection hoops.

The Verdict: Not a hard-core 911, but nice.

Add great seats, an intelligent ride-and-handling compromise, and a high equipment level without unnecessary complication of the car’s interior, and it’s easy to see why Porsche just reported the best-ever 911 monthly sales figure in its U.S. history.

2006 Porsche 911 Carrera
300-hp flat-6, 5-speed automatic, 3460 lb
Base/as-tested price: $82,195/$95,615
60 mph: 5.2 sec
100 mph: 12.5 sec
1/4 mile: 13.8 @ 105 mph
Braking, 70­–0 mph: 150 ft
Roadholding, 300-ft-dia skidpad: 0.92 g
C/D observed fuel economy: 16 mpg

First Place: Mercedes-Benz SL550

The ’07 Mercedes-Benz SL is powered by the new-generation four-cam 32-valve V-8 also seen in the redesigned S-class cars. In the SL550 it produces 382 horsepower—fully 80 horses up on the previous model. The new engine also allows installation of a seven-speed automatic transmission with manumatic override that is capable of gearshifts 30 percent quicker than before.

Highs: Big torquey engine, brilliant transmission, solid build, lucid steering feel.

The steering was retuned with faster response and revalved assistance for better feel, and the active-body-control (ABC) system was recalibrated to be 60 percent stiffer in roll in the sport driving mode. These are upgrades you can feel at every tactile interface with this car, and they provide better feedback to the driver without hurting the SL’s exceptional refinement. The excellent retractable hardtop required no revisions.

But just as with the Porsche 911, the hearts of our unemotional drivers had to be won over during the course of the test. Initial comments slated the SL for numb steering, hard-to-read brake-pedal feel, and a general sense of weightiness. One politically incorrect guy even had the effrontery to suggest that the SL was “like dancing with a fat lady. She can do it, but you won’t win any prizes.”

At 4180 pounds, the SL is the second-heaviest car in the group (beaten only by the porky BMW 650i), and its lane-change performance conformed exactly to those rankings. Its skidpad grip, too, came in second to last, at 0.84 g. But the SL’s stability system cannot be disengaged, and that undoubtedly plays a part.

Out in the wiggly bits of asphalt laughingly referred to as the highway, none of this seemed to matter. In fact, the remarkable transformation was greeted with these words: “Very entertaining for a car so aloof in the city. Really comes alive.

Indeed, it does. The SL bit into curves with steering feedback that made most of the other cars feel like video games. We hardly bothered with the manumatic buttons, because the adaptive facility in the full-automatic mode is so intelligent—psychic, even—that it seemed to sense our every need. If you’ve been tramping along, the tranny will hold gears for high-rev shifts, even at less than full throttle, and it’ll let you back off for a corner entry without an upshift so you can nail it hard at the exit.

Lows: The sticker (as usual).

Even the brake-by-wire system felt lively during sporty driving, with plenty of bite and easily read modulation. And best of all, that 5.5-liter V-8 feels as if it were tweaked by the AMG magicians, capable of strong low-rev thrust along with a hearty rush to the redline. And did we mention that the sound effects are music to the ears?

For a comparatively large and heavy car, the SL seems to shrink at a quick pace in challenging terrain. Its cockpit is comfortable and roomy, even as the windshield, dashboard, and controls are all at an intimate proximity. The seats are excellent, with firm cushioning and supportive contours, and the active-body-control system is so effective you feel g-forces as pure lateral thrust.

This Mercedes is deceptively quick, so fast it led us down Route 58 through California’s Kern County at such a brisk pace that the car got air over a whoop we’d never negotiated so fast before. It wasn’t that high, and the car greased the landing like an airline professional, but the onboard safety sentinels saw suspensions at full droop and popped the roll-protection hoop. That was the extent of the drama.

The Verdict: Convincingly superior in so many ways.

When you add those vigilant (but not intrusive) safety systems to everyday refinement, a transcendent high-performance personality, comprehensive equipment levels, and unimpeachable solidity, you have a class-leading combination. Among high-end convertibles, this one commands the highest currency.

2006 Mercedes-Bens SL550
325-hp flat-6, 5-speed automatic, 3460 lb
Base/as-tested price: $82,195/$95,615
60 mph: 5.2 sec
100 mph: 12.5 sec
1/4 mile: 13.8 @ 105 mph
Braking, 70­–0 mph: 150 ft
Roadholding, 300-ft-dia skidpad: 0.92 g

C/D observed fuel economy: 16 mpgThis content is created and maintained by a third party, and imported onto this page to help users provide their email addresses. You may be able to find more information about this and similar content at piano.

Per: Car and Driver

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