Racing Green Cars

Jaguar XK8/XKR 1996-2006

Overview

One reason for the XJS’s extraordinarily long production run was that its intended successor never made it into production, at least not as a Jaguar anyway. Codenamed XJ41/42, the original concept was for a re-bodied XJS floor pan fitted with a twin turbo AJ6 engine and four wheel drive, but, in truth, it was too complicated for production and following the Ford takeover in 1990, the new management decided to scrap the project and start again. The basic design did however survive in much simpler form, as the Aston Martin DB7. Jaguar went back to the drawing board, but this time with funds to develop an all new V8 engine.

The XK8 in many ways is an amalgamation, retaining elements of the XJS floor pan, but with XJ40/X300 rear suspension, an entirely new front suspension layout that combined double wishbones with a coil over damper assembly, and the new quad cam V8 engine - all housed in a curvaceous body that clearly drew its inspiration from the E-type of three decades before.

The heart of the car was the 4.0 litre engine. All alloy, it dispensed with conventional steel cylinder liners in favour of a nickel silicone (Nikasil) coating that had been used successfully for many years in motorcycle engines. Each cylinder head had twin camshafts - the inlet cam timing variable via electro hydraulic actuators - and 16 valves, with the now familiar coil on plug ignition system. The cylinder block was equally advanced with a bed plate, incorporating the bearing caps for increased stiffness and radical new cooling system for rapid warm up and reduced emissions. Time unfortunately has shown that both the Nikasil bores and lightweight timing chain layout were not sufficiently robust for real world driving conditions with a large number of failures; the Nikasil coating being broken down by high sulphur petrol, leading to a loss of compression, while upper timing chain tensioners would break up, causing the chains to potentially skip a tooth in their unsupported state. Jaguar extended its engine warranty to 100,000 miles in order to restore confidence and prop up resale values.

The transmission was also new. Built by ZF, it now had five gears and, according to the manufacturer, was supposedly sealed for life, though that has since proven somewhat erroneous with many gearboxes failing prematurely due to oil degradation.

While the rear suspension carried over virtually unchanged from the saloon range, the front was entirely new with an aluminium cross member, two piece lower wishbone and strut mounted springs that fixed directly to the body shell. An optional CATS suspension system used sensors to determine how the car was being driven and then instantly switch adjustable dampers from soft to hard should the driver start to press on. ABS and traction control were of course standard, along with Dynamic Stability Control, which used a sensor to determine the direction in which the car was travelling, compared that with the direction in which the front wheels were pointing and should it detect a skid, brake individual wheels in order to regain control.

From the driver’s seat, the view was dominated by a huge swathe of timber across the dashboard, allegedly inspired by the wing of a Spitfire, into which the three main instrument recesses, centre air vent and ancillary gauges were set. Other than the window switch surrounds, there was no other wood in the car, all styling achieved through different shades of vinyl and carpet. Rear seat space remained tight but the boot could now accommodate two sets of golf clubs, though at the expense of a slightly bulbous rear, only partly disguised by a steeply angled bumper moulding.

At the launch in 1996 there were only two models, coupe and convertible, the latter retaining a traditional canvas folding hood for a traditional look and maximum boot space.

By 1998, the naturally aspirated cars had been joined by a supercharged variant, the XKR, with 370bhp and a new Mercedes-sourced automatic transmission; this was now the most powerful Jaguar sports car ever, by a significant margin, and came with 18 inch wheels as standard, along with bonnet vents, mesh grille and a small boot lip spoiler. For those who wanted even more, a range of R-Performance upgrades offered split rim BBS alloy wheels up to 20 inches in diameter, along with a high performance Brembo brake package.

While there had been considerable changes under the skin, especially in relation to the engine management system, in 2000 came the first significant facelift. With jewel effect tail lights, improved front seats with separate headrests plus flush fitted front fog lights. One update not publicised was the revision to steel cylinder liners in August of 2000. Other notable developments in technology included satellite navigation, adaptive cruise control that could maintain a set distance to the car in front, and sensors to establish the size and position of a passenger and in the case of an accident adjust the airbag deployment to suit.

For 2003 the V8 engine was significantly redesigned, with capacity increased to 4.2 litres and an entirely new timing chain setup that used alloy tensioner casings and a more robust Morse type chain with additional lubrication. Power was now up to 300bhp for the normally aspirated cars and 400bhp for the supercharged XKR. All cars were fitted with a new six-speed ZF gearbox. Inside there was now the option of carbon fibre or piano black veneer in place of the traditional polished walnut.

For 2004, the nosecone was redesigned with more prominent mesh and sill covers fitted to visually lower the car’s stance, while the XKR now featured quad exhaust pipes.

There were three significant special editions over the years, beginning with the XKR ‘Silverstone’ in 2000 to celebrate Jaguars involvement in Formula 1 and featuring Platinum paint with red stitched black interior and 20 inch BBS wheels along with suspension and brake upgrades. The black on black XKR 100 followed in 2001 to mark the centenary of Sir

William Lyons birth and as with the accompanying XJR 100, also included BBS wheels and Brembo brakes. Finally, to mark the end of the series there was the XK 4.2S (Victory Editions in the US), available in both naturally aspirated and supercharged forms. These cars came with new colour and veneer options, special badging and new wheel designs, 19 inch for the XK8 and 20 inch for the XKR

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Specification

Click to view the specification for each model

Engine

4.0 V8

Capacity

3996cc

Max Power

290bhp @ 6100rpm

Max Torque

290 lb ft @ 4250rpm

Performance

0 - 60 mph

6.4 seconds

Max Speed

155mph (limited)

Fuel Economy

23.8mpg

Engine

4.0 V8 Supercharged

Capacity

3996cc

Max Power

370bhp @ 6150rpm

Max Torque

387 lb ft @ 3600rpm

Performance

0 - 60 mph

5.2 seconds

Max Speed

155mph(limited)

Fuel Economy

23.1mpg

Engine

4.2 V8

Capacity

4196cc

Max Power

300bhp @ 6000rpm

Max Torque

310 lb ft @ 4100rpm

Performance

0 - 60 mph

6.1 seconds

Max Speed

155mph (limited)

Fuel Economy

24.9mpg

Engine

4.2 V8 Supercharged

Capacity

4196cc

Max Power

400bhp @ 6100rpm

Max Torque

408 lb ft @ 3500rpm

Performance

0 - 60 mph

5.2 seconds

Max Speed

155mph (limited)

Fuel Economy

22.9mpg

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