Cars.comparison: High-Roller Convertibles

Sometimes, money really is no object. When that's the case, a luxury convertible is one of the best ways we can think of to spend some of those extra Benjamins lying around collecting dust. Here, Jaguar's all-new XK convertible squares off against the BMW 650i ragtop and Mercedes-Benz's SL550 retractable-hardtop. Does it have enough panache to come out on top? Read on to find out.

 = Category winner
The Contenders
2007 BMW 650i automatic2007 Jaguar XK2007 Mercedes-Benz SL550
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Price as tested
Acceleration* (zero to 60 mph)
5.7 seconds. The 650i's V-8 makes big-time power like the Mercedes, and the BMW is the only one of the three with an available manual transmission if you'd rather shift it yourself.6.0 seconds. The slowest zero-to-60 time is reflected in our seat-of-the-pants impressions: The XK's power isn't stunning, but it's well-matched to the car. The transmission, though, is one of the best automatics we've driven — anywhere. 5.3 seconds. The free-revving 5.5-liter V-8 engine makes broad waves of power, but the automatic transmission's tendency to upshift to a higher gear than necessary can rob the V-8 of some of its gusto.
Gas mileage (city/highway, mpg)
17/25 18/2714/22
Ride and handling
Like most BMWs, the 650i hugs the road and communicates the driver's steering commands with pinpoint accuracy. It doesn't, however, mute bumps like a cruiser — this is a bruiser. Body roll during hard cornering is practically nonexistent, and the suspension soaks up bumps in the road without punishing occupants. The XK has a long nose, and that takes some getting used to. Of three heavy cars, this one is and feels the lightest, yet the most grounded.Mercedes' Active Body Control keeps the roadster flat when cornering, and quick steering response enhances this luxury roadster's sportiness. The SL's considerable weight, however, makes it feel less nimble than expected.
Top up/down appearance
The soft-top's lines are reasonably smooth, but the car really wows when the top is stowed beneath the rear deck lid. While the styling polarizes within automotive circles, common folk rave about the redesigned Jaguar. The XK looks terrific with the top down, and even with the top up it exudes modern British style. A retractable hardtop like the SL's is still fascinating to see in action, but the Mercedes is the oldest model of the three and it doesn't have the visual impact of the Jag.
Power-top operation and trunk space
The BMW's trunk is the largest of the three at 12.4 cubic feet, though it shrinks to 10.6 with the top down. Its shape makes it the most usable — and the winner. Lowering the fully automatic top takes about 25 seconds, as does raising it. The XK's low-slung lines make it a looker, but it doesn't do much for the trunk, which is shallow and the smallest of the bunch at 10.0 cubic feet. With the flimsy divider partition raised and the top lowered, it's just 7.1 cubic feet.The SL's retractable hardtop packs itself into the trunk in a brief 13 seconds, but takes 19 seconds in reverse. Capacity is 10.2 cubic feet, but that shrinks to 7.3 with the roof lowered. Though it grants access to what space remains, the roof panels take up a lot of room.
Comfort and roominess
The front seats are wide and have sufficient side bolsters for sporty driving, but the cushioning is lumpy and it was harder to get comfortable in this car than in the other two. The small rear seats are better used for storage.
The Jag's seats perfectly straddle the fine line between supportive and comfy, with a nice leather covering and many adjustments — all within sight as well as reach. The seating position is a slung-back affair with the driver looking over that long hood.
The highly adjustable front bucket seats provide firm support. The only roadster of the three, the SL's cabin isn't cramped, but it is intimate.
Interior quality
BMW is BMW. Not much changes from model to model; there are lots of black buttons everywhere on the dash, and things are a bit too stoic for the wind-in-the-hair crowd. Overall quality is good, though, and that's enough to beat the other two.The XK wins praise for its use of different wood grains and a nice gauge cluster and central touch-screen LCD, but some materials and buttons are widely criticized.While there's beautiful craftsmanship on the dashboard and center console, there are elements like cheapo vinyl sun visors that don't belong on a six-figure car.
Overall value
In this price range, you expect things like heated seats and a multi-disc CD changer to be standard, but neither is in the BMW. The 650i does have the best warranty of the three, however. The XK is reasonably well-equipped for the price, and you can't overlook its significant advantage in gas mileage, which pays dividends from the start.The premium for the three-pointed star is steep, but beyond the SL's retractable hardtop, there's little to justify the as-tested price when matched against the BMW and Jaguar.
Editors' choice
The 650i's unique styling, eager V-8 and overall driving experience put it in a horse race with the XK, but the effort staffers expended to get behind the wheel of the BMW was nowhere near as rampant as it was with the Jag. That speaks volumes. The most important requirement of a high-end droptop is that it must make the driver look and feel like a somebody, and the XK does so better than either the BMW or Mercedes and makes no sacrifice in the driving experience.Apart from the price, the SL-Class has always done what its competitors can do ... technically. But it's never been a car in which all performance aspects are perfectly matched. The driving experience is lacking.
*Manufacturer data
Posted on 8/1/07
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