Jaguar XJ sedans switch to aluminum for a lightweight frame
Bob Plunkett
Date Posted: 5/10/2005
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SEVILLE, Spain -- Sensuously shaped sedans, Jaguar's flagship XJ series in a new style for 2004, stand side by side on a ramp at the airport in Seville, Spain, where a jet deposits us following a flight from the Jaguar factory that assembles these new XJ cars in Birmingham, England.
With the ignition key already engaged and a powerful V8 engine purring, the XJ8 sedan we choose for a test drive -- painted a high-gloss ebony with the leather-lined cabin trimmed in shades of sable and sand -- is ready to roll. So we're off in seconds, pausing only long enough to adjust contours of the luscious driver's seat and set mirrors and the leather and wood steering wheel for a custom fit.
A brief shot westward on the divided E5 freeway quickly reveals that this newest Jaguar comes with the strength of a supercar to run lickety-split at speeds that would be taboo on American highways while it also maintains a refined atmosphere of civility and comfort in the ultra-quiet cabin.
Then at Carmona, we head north on A457 and cross the meandering Guadalquivir at a whitewashed village named Lora del Rio, then pick up narrow A431 as it follows the curvy river eastward through rolling Andalusian hills.
This undulating route demonstrates that the new Jag also behaves itself nicely in the curvy stuff, rear wheels throwing muscle into each turn as the tires claw for traction on a blacktop surface.
Slip that shift lever down a notch through the manual mode and the engine whines in braking before the next turn. Then ease into the throttle after the apex and exit cleanly before punching it into the proceeding straightaway.
Now hold on tight: This thing tracks like a cat through these curves and can fly when unbridled.
For a large car, and a supreme luxury liner at that, such sport-tinged flavor is definitely not what's expected here. However, pleasant surprises and driving excitement seem to come together with extensive luxury features heaped into the new design for Jaguar's XJ sedans.
But the news here is not so much about keen performance and sporty manners, which the car obviously possesses, as it is about spatial expansion of the five-seat cockpit and the unconventional unibody structure composed of lightweight aluminum rather than weighty steel.
Early in the design process when developing a new generation of XJ sedans, Jaguar's engineers realized that a switch from steel to aluminum for the car's structural elements would trim considerable weight off the chassis.
So it does, as the aluminum-based XJ8 tips scales some 200 pounds less than the previous model built from steel.
Choosing aluminum as the car's building blocks also forges a stiffer structure because it's put together with aluminum rivets and heat-cured glues in techniques lifted from the aerospace industry to create an ultra-rigid frame measuring 60 percent stiffer than a similar body crafted in steel.
Enormous aluminum presses at Jaguar's Castle Bromwich body assembly plant in Birmingham stamp out one-piece bodyside panels stretching from tip to tail, as well as other components including frame and cross brace supports, roof, hood and decklid. All come together to forge the rigid and lightweight structure.
The package size grows considerably in all dimensions. It's longer and wider and taller than the predecessor with more cabin and trunk space.
Anyone familiar with the shape of the previous XJ8 will instantly recognize the curvy new version as a bold-faced Jaguar with the signature prow cut by pairs of oval articulated headlamps flanking a twin-port grille, smooth lines sweeping rearward across a long hood and low roof, and a rounded boat-tail back.
Yet the rump varies from tradition by nixing a sagging tail in favor of a trunk with less slope to the deck.
It carries unique light-emitting diode (LED) taillamps in the first use for a Jaguar. Set behind clear lenses, the LED lamps look brighter than incandescent bulbs and they light up twice as quickly. When applying brakes at 60 mpg, for instance, the quicker flash point for brake lights works out to more than 17 more feet of warning distance for a driver trailing behind, and that becomes a safety issue.
Jaguar delivers three variations in the XJ series to the North American market. XJ8 is the primary model but a dressy version restores the marque of Vanden Plas to the line and a performance edition with supercharged boost wears the badge of XJR.
Powertrains come from Jaguar's dual-cam 4.2-liter V8 engine with all torque translated through a sophisticated ZF six-speed electronic automatic transmission.
The transmission shift lever, rigged with Jaguar's venerable J-pattern gate for automatic and manual shifts, isolates various gear positions so you may shift it yourself without clutching, if desired.
XJ8 and the Vanden Plas edition stock the naturally aspirated V8, which delivers as much as 294 hp at 6000 rpm plus torque of 303 lb-ft at 4100 rpm.
That's good enough to propel these sedans from a standing start to speed at 60 mph in only 6.3 seconds.
XJR the performance model adds an Eaton Roots blower to the V8 as well as dual air-to-water inter-coolers. As a result, it gushes to 390 hp at 6100 rpm and pushes the torque out to 399 lb-ft at only 3500 rpm.
This supercharging affects the car's performance, for the zero-to-sixty time drops to five seconds flat.
Variable-assist power rack and pinion steering and four-wheel disc brakes with computerized anti-lock controls (ABS) and electronic brake distribution (EBD) improve motion maneuvers for all models. A dynamic stability controller (DSC) is also in place, along with an air suspension and Jaguar's computer active technology suspension (CATS).
XJR goes further by adding Brembo disc brakes and 19-inch alloy wheels capped by Pirelli P-Zero Rosso tires, plus xenon high intensity discharge (HID) headlamps.
Standard cabin appointments for all include leather upholstery and elegant burr walnut wood trim, adjustable pedals with memory settings also governing driver's seat, steering wheel and mirrors, a rear park distance control monitor, power moonroof and a new electronic parking brake in place of the traditional handbrake lever.
Vanden Plas gets even more, like soft-grain leather, heated seats, a power sunblind, 16-way power for front seats and an Alpine audio system with six-disc CD deck.
An optional LCD screen in the dash has a touch screen for controlling climate, audio and optional navigation system or cellular telephone. Further, a DVD-based entertainment system for rear riders uses dual video screens mounted in headrests over the front seats.
Jaguar sets the MSRP point for new XJ8 at $59,995, or $74,995 for XJR.
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| 2004 JAGUAR XJ8 VEHICLE SPECIFICATIONS |
| Description: |
Full-size luxury sedan
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| Model Options: |
Full-size luxury sedan
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| Wheelbase: |
119.4 inches
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| Overall Length: |
200.4 inches
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| Engine Size: |
XJ8: DOHC 4.2-L V8
VP: DOHC 4.2-L V8
XJR: DOHC 4.2-L V8 SC
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| Transmission: |
XJ8: Auto/6 ZF
VP: Auto/6 ZF
XJR: Auto/6 ZF
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| Drive: |
Rear
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| Braking: |
XJ8: Power 4-disc/
ABS/EBA/TCS/DSC/CATS
VP: Power 4-disc/
ABS/EBA/TCS/DSC/CATS
XJR: Brembo 4-discs/calipers
ABS/EBA/TCS/DSC/CATS
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| Airbags: |
2 (front) + 2 (side)
+ 4 (side curtain)
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| Gas Mileage: |
XJ8: 18/28 mpg
VP: 18/28 mpg
XJR: 17/24 mpg
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| MSRP Price: |
XJ8: $ 59,995, VP: $ 68,995, XJR: $ 74,995 |
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