New Zealand to wait for 4x4 Jaguars
In the United States and Canada, keen motorists are so aware of the difference between winter and summer driving conditions they often have an extra set of tyres and wheels to change as seasons and weather conditions dictate. It's the same in Europe, and in Germany there are areas where is is illegal for motorists to drive on non-cold weather tyres between certain winter dates.
Those markets also show a trend towards buying ordinary sedans and wagons - as opposed to SUVs - with all-wheel-drive (AWD) options, and from next year, Jaguar says it is to supply AWD versions of its XF and XJ saloons in selected markets.
Having noticed the North American and European trends, where winter traction is a major catering point when selling cars, Jaguar says its AWD cars will be offered where consumer demand is highest. The company realises this is dictated by climate and it's keen to supply to the AWD market where it will increase the appeal, not to mention the capability and versatility of the XF and XJ in conditions where grip is compromised.
North America, Russia, China and continental Europe will account for the majority of sales for the new AWD models powered only by Jaguar's new 3.0-litre V6 supercharged 250kW petrol engine for the time being.
Adrian Hallmark, global brand director, Jaguar, said: "Jaguar has revitalised its core range and is now undertaking an intensive programme of introducing new models, strategic powertrain and technologies to reinvigorate the Jaguar brand around the world.
"The new AWD products are another example of how we are taking the Jaguar business forward by thinking globally and targeting specific market opportunities by addressing specific regional requirements."
The US is the world's leading market for AWD sales and initially more than three quarters of the AWD models produced at Jaguar's Castle Bromwich factory in the United Kingdon from October 2012 will be sold in the US.
With the new addition to the XF and XJ ranges, Jaguar will compete in approximately 80 per cent of the luxury saloon market, four times its previous opportunity.
Jaguar's new AWD system has been developed by using Land Rover expertise in AWD systems, and is based for the time being around the new 250kW 3.0-litre V6 supercharged petrol engine, driving through a ZF eight-speed automatic gearbox and using Jaguar's Intelligent Stop/Start system.
The AWD system is rear-wheel drive-based and has undergone 18 months of extensive cold weather and all-surface testing to ensure steering integrity and suspension refinement are unaffected. The longitudinal engine installation means Jaguar's engineers were able to retain the rear axle as the primary drive path, with a multiplate clutch within the transfer case apportioning torque to the front axle as dictated by grip conditions and driver inputs.
The primary benefit is that both the AWD XF and XJ can remain as agile and communicative as their rear-wheel drive siblings with, says Jaguar, no dilution of steering feel or feedback. In dry road conditions the system will deliver drive predominantly to the rear axle while constantly monitoring grip levels, steering and throttle inputs, allowing it to intervene should it detect the possibility of wheel-slip, when it will deliver torque to the front axle to maximise traction.
The system works with Jaguar Drive Control, which allows the driver to select winter mode that pre-warns the system that traction may be compromised and causes it to allocate a greater proportion of drive torque to the front axle. Integration with the Dynamic Stability Control and anti-lock braking systems also allows each wheel to be braked individually and torque apportioned from side-to-side across each axle.
The sole external differentiation between AWD and rear-wheel drive XF and XJ models is the addition of "3.0 AWD" badging on the cars' bootlids. The AWD system is available with both standard and long-wheelbase derivatives of the XJ.
Providing the power for the AWD system is a new all-aluminium 3.0 V6 supercharged petrol engine, which delivers 250kW at 6500rpm and 450Nm of peak torque from 3500 to 5000rpm, 400Nm of which is available from just over 2000rpm.
The AWD system uses the eight-speed automatic gearbox, standard on all XF and XJ models, but modified to accept the fitment of a transfer case with an active coupling that directs torque to a front propshaft, front differential and halfshafts.
The multiplate wet clutch directs torque through the front propshaft as dictated by the Transfer Case Control Module (TCCM), which monitors grip levels and driver inputs, apportioning the torque front and rear as appropriate.
A new front knuckle design allow the directionality and feedback of the steering systems to replicate the rear-wheel drive XFs and XJs. The front suspension has new springs, dampers and anti-roll bars, while at the rear, suspension springs and dampers are modified while the XJ is fitted with a new anti-roll bar. Both models receive a recalibration of the software controlling the Adaptive Dynamics suspension system.
In dry road conditions, the AWD system operates in such a manner that all the dynamic qualities of the rear-wheel drive models are preserved by prioritising torque delivery to the rear axle. The exception to this is on pull-away from rest, when a pre-load torque is always applied to the front wheels to ensure smooth, fuss-free and consistent initial acceleration.
This is governed by the feed-forward element of the control algorithms, whereby situations in which wheel-slip might occur are predicted and accounted for by delivering torque to the front wheels as a pre-emptive measure to eliminate the possibility of a loss of grip.
The system constantly monitors road conditions, throttle and steering inputs and should any slip be detected between the front and rear axles the TCCM will automatically apply reactive feed-back torque to negate any difference in front and rear wheel speeds. The maximum torque split is 50:50 front to rear.
When operating in winter mode the feed-forward function is strengthened to pre-empt the possibility of wheel-spin. In addition, the Dynamic Stability Control system constantly monitors wheel-slip across each axle and uses the anti-lock braking system to selectively brake each of the four wheels as necessary to prevent wheel-spin.
Jaguar Drive Control also offers the enthusiastic driver the option of Dynamic mode in which throttle response is sharpened and the gearbox is instructed to upshift more quickly and at higher revs. Dynamic mode also firms up the damper settings in vehicles equipped with Adaptive Dynamics to deliver more precise, controlled body movements to enhance handling.
With AWD occupying less than 5 per cent of the UK luxury saloon market, the AWD XF and XJ will not be offered in the UK for 2013 model year.
Other right-hand drive markets like ours, Australia, South Africa and Japan's are also likely to have to wait for all-wheel-drive versions, for the same reason that BMW and Mercedes-Benz don't offer AWD for its sedans and wagons in RHD.
We simply don't buy four-wheel-drives in big numbers unless they're SUVs or trucks.
Start writing to your dealer now, folks.
- © Fairfax NZ News
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