13th February 2013
In an article entitled ‘Driven to Success‘ which discusses Jaguar Land Rover’s strong growth and continued expansion, Professional Engineering gives some interesting details how the company is meeting it vehicle weight challenges.
Like many car makers, Jaguar Land Rover has been very vocal about its efforts to reduce the weight of its vehicles to improve fuel efficiency and reduce emissions. For example, last year the company announced that the new Range Rover would feature an all aluminum body which would save 420kg (926 lbs) over the previous model. The article gives a good overview of some of the techniques that are being employed and the impressive results being achieved. We’ve featured a exert from the article below but would recommend going over to Professional Engineering to read the full story.
A second area of intense research and development effort is around lightweighting. JLR is pursuing the trend towards downsizing to meet stringent emissions reduction targets, shifting from V12 to V6 and V4 engines, without any loss in vehicle performance. That magic formula can only be achieved if advancements can be made in several tandem areas of technology, including lightweighting.
Those efforts are overseen by Mark White, head of materials at JLR. He says that, broadly speaking, JLR wants to produce cars that weigh less than 1,500kg and SUVs under 2,000kg. Longer term, those figures need to come down to 1,000kg and 1,500kg respectively.
How might that be done? Well, JLR believes that there is still some weight-saving potential from the development of new steels. “We can probably still get a 10-20% weight reduction potential in the body of a chassis from new high-strength steels,” says White. “For example, we saved 70kg on the Evoque versus the Freelander through the use of next-generation ultra-high strength steels.”
But to make real leaps in weight saving, JLR will continue to pursue the wider use of aluminium and the further introduction of more exotic metals such as magnesium. “We believe that with aluminium we can get at least a 40% weight saving, technically 50%,” he says. “And then there is magnesium, that offers further weight reductions, possibly another 10% over aluminium. But magnesium has some issues with joining and erosion and other challenges. So at the moment magnesium is still restricted to use for bolt-on components such as front-end carriers and cross-car beams.”
Looking further forward, JLR says carbon fibre and reinforced plastics bring real potential for lightweighting on the body and chassis. However, at present, carbon fibre is prohibitively expensive for all but the makers of very top-end supercars. The Aston Martin One 77 coupe, for instance, features a full carbon monocoque chassis that reportedly costs a six-figure sum per vehicle. Other carmakers such as Lamborghini and McLaren have also launched supercars with extensive carbon-fibre content.
White is realistic about the impact that carbon fibre will have on more mainstream markets. “Over time costs will come down,” he says. “But even using the very best roadmap that the car industry has got, we still think a sub-£10,000 carbon-fibre structure for a new premium vehicle is going to be a challenge, and to get down to the low thousands of pounds will require a concerted effort.”
Efforts to increase carbon-fibre content are under way, and will feature on the CX75 hybrid-electric, two-seater prototype. JLR is experimenting with carbon fibre on the tub and frame and on the cross-car beam, undertrays, bumpers, seat-frames and on some of the trim. “The CX75 is our own concept – we are looking at what the weight-saving potential versus the cost might be,” says White. “We want to know what the barriers are to producing something like a future XK with carbon-fibre content in volumes of between 1,000 and 10,000 cars. And going even further into producing maybe a city car somewhere in the future.