ANALYSIS: Jaguar Land Rover's lightweight future
The F-Type Coupe’s body sides are single-piece aluminium pressings, fabricated from high-strength and formable AC600 aluminium, which has also been used for structural reinforcement – both engineering firsts for Jaguar.
Tata's UK-based Jaguar Land Rover (JLR) unit has grown volume and profit in recent years, underpinned by successful model range additions and sales expansion around the world. Ian Adcock lifts the lid on the increasing importance of aluminium in JLR's future product strategy.
Having recently posted pre-tax profits of GBP1,675m, up 11% over last year, and announced an investment programme of GBP2.75bn with a view to introducing eight new or refreshed products this year alone, it’s challenging to recall this is the same business that went cap in hand, unsuccessfully, to the Blair government for a loan to bail it out during the height of the global financial crisis in 2009.
More recently, every press release that Jaguar Land Rover issues seems only to trumpet yet another success or expansion. Last year it announced plans for manufacturing in China and Brazil, and is constructing a GBP500m engine plant in the UK.
The plant in Brazil will have the capacity to build 24,000 vehicles annually for the Brazilian market, with the first vehicles (model not yet specified) off the line in 2016. It has also announced that its range-topping Jaguar XJ saloon will be built for the Indian market at JLR’s plant in Chakan, near Pune.
Customers are flocking to all three marques in their droves, eschewing the global ubiquity of Germany’s three premier brands for a more exclusive club membership. But, underlining the design leadership of Ian Callum for Jaguar and Gerry McGovern at Land Rover there is an engineering ethos in the intelligent use of lightweight materials, specifically aluminium, that one could argue is at least equal to, and they would say privately, better than their rivals.
JLR’s expertise in aluminium and, specifically, Jaguar’s dates back to its time as part of the Ford empire and its Aluminium Intensive Vehicle (AIV) programme of the 1990s.
In addition to the development work into aluminium monocoques that Ford had carried out in its own AIV and P2000 programmes, Jaguar also had its own reasons for going down the path it did rather than producing a spaceframe structure similar to Audi's as it didn’t want to appear to be a ‘me too’ company following in the German’s wheel tracks.
Jaguar’s breakthrough with the technology underpinned the 2003 XJ, but the saloon’s conservative styling overshadowed the undoubted excellent use of aluminium structures.
It really wasn’t until the much sportier, and more contemporary looking, XK arrived two years later that Jaguar’s pre-eminence in employing aluminium to minimise weight was truly noticed. But there’s much more to the use of this lightweight material than just minimising body-in-white mass. And, of course, it shouldn’t be forgotten that Land Rover pioneered the use of aluminium as far back as 1948 with the original Defender built from aluminium recycled from war time aeroplanes at Solihull.
For Mark White, JLR’s chief technical specialist body structures, aluminium body structures are the outward face of a new, greener, more efficient manufacturing process that stretches right across the supply chain: “Our sustainability strategy is not just focussed on the product itself, but parts manufacturing and in the plant and through our suppliers, real total lifecycle approach,” and that applies equally to both Jaguar and Land Rover products.
Talking at the latest Range Rover launch, White put the marque's increased us of aluminium in context. “There’s a 72 per cent increase in the amount of sustainable materials recycled over the current car, right across the whole vehicle. We didn’t set out by saying it had to be that, but we wanted to make the car not only appeal to the customer from a driving point of view but, also, really wanted to improve the credentials of Range Rover as a vehicle and a brand in terms of its sustainability and its outward face in terms of facing up to the environmental challenge. And we made every effort we could in all areas of the car to make it more sustainable.
“We can’t just pretend the carbon problem doesn’t exist, we have to face up to that and address it in a holistic way. We want to give our customers the type of car they want to drive, we don’t want to make Fiat 500s, we want to make Range Rovers but we want to make Range Rovers that are truly environmentally friendly.”
This strategy equally applies to Jaguar products such as the F-Type built at Castle Bromwich, Jaguar’s fastest and most modern production facility. Because no welding is involved there’s a 70 per cent saving in the amount of energy required than if it had been resistant spot welded. It also means that because it’s a very clean process, the body-in-white assembly can share the same facility as trim to give a very connected manufacturing process with quicker feedback during production.
Moreover up to 50 per cent of the metal used on the F-Type is recycled, and that uses only about a tenth of the energy that prime metal requires to give the F-Type one of the lowest carbon footprints of any sports car. That’s the same target JLR set for themselves with both the latest Range Rover and XJ saloon, but the group has ambitious plans to increase that to 75 per cent recycled metal by 2020. “That’s a big walk for us,” admits White, adding, “we’re working on various projects that are in pilot or research phase that will allow us to do that and the great thing is that our main supplier, Novelis, has said that it’s up for the challenge and has publicly stated that its goal is to get from 75 to 80 per cent recycled metal supplied to us. They’re on the journey as well and working with us.”
That strategy is equally applicable to suppliers like Walsall pressings, Sertec and Stadco who need to recycle their aluminium to put even more reprocessed metal into the loop.
“We’ve tried to apply the same mentality and rigour to the supply chain as we have done to ourselves. We’ve asked all of our suppliers to adopt the same joining technologies, to look at recycling the scrap they produce and make sure they’ve got closed loop recycling in their factories and making sure they minimise their waste wherever in their part of the production phase,” White explains.
JLR’s three latest products, the Range Rover, Range Rover Sport and F-Type represent the latest stage in the evolution of its lightweight strategy as White explains. “In the past we focussed on saving body weight; I think now we’re into saving weight on the whole vehicle so the obvious thing to do was to look at the sub-frames, corner geometry, knuckles, wishbones and look at how much weight we can save on them. With the added advantage that the more unsprung mass/weight you save the better it is from a dynamics point of view.
“The sub-frames are now a combination of extrusions and castings, using multi-process approach. We tried to look at how much integration opportunity can we get from using those type of materials.”
As both the Range Rover Sport and F-Type share the same production facilities as their siblings – the Range Rover and XK, respectively – it would be easy to assume there is a high percentage of shared parts, but wrong.
According to the Sport’s chief programme engineer, Stuart Frith, there’s a 75 per cent part count difference with the Range Rover. The most obvious are the body panels, but from an attribute perspective there are stiffer engine mounts, re-tooled suspension to deliver an 8mm lower ride height, a new magnesium front carrier that allows a lower bonnet height but still delivers EuroNCAP 5-star pedestrian impact as well as a multi CAN system replacing the range Rover’s twin CAN arrangement.
Both are produced at Land Rover’s all-new body shop at Solihull, part of a GBP370m investment in the site which also includes a new paint shop. With a potential 120,000 a year capacity running three shifts there’s plenty of scope for expansion to include Land Rover’s burgeoning model line up that will include a radical upgrade of the Discovery which, inevitably, will follow the aluminium path at some point in the future.
At Frankfurt last year, Jaguar displayed its fifth generation aluminium platform under the guise of the C-X17 soft-roader. Dubbed iQ Al it will underpin JLR’s new range of smaller products starting with Jaguar’s BMW 3-Series challenger in 2015.
Compared to the aluminium structures of its premium products, iQ Al incorporates a higher proportion of sheet aluminium and fewer castings and extrusions whilst technologies include further advances in adhesive bonding, rivet bonding, clinching and welding.
According to vehicle line director Kevin Stride, a whole new library of alloys, including 6000 and new 7000 series deliver more specific strength enabling iQ Al to achieve excellent stiffness and the unusual ability to achieve both 300Km/h and under 100g/km CO2. Although 7000 series aluminium is currently at the development stage it has the potential to deliver 40% weight saving for the same crash resistance as steel.
However, there is more potential for this platform: not only will it form the basis of Jaguar’s new small saloon, but it will underpin the marque’s first soft-roader due in 2016 and could provide Range Rover with the potential for a product between Evoque and Range Rover Sport or, even, a sub-Evoque model to rival Audi’s Q1 due in 2016.
Whilst the F-Type shares its production facilities with the XK it, too, is a significantly different beast to the larger GT says director, Jaguar programmes, Ian Hoban. “From a structural platform perspective we refer to this as the fourth generation of our aluminium architecture so to say it’s an evolution from XK is not accurate. Since the original XJ back in 2002 we’ve been developing and refining the architecture and the bottom line is how much stiffness can you get out of the structure in key areas for a given weight?”
As with the Sport, the F-Type differs significantly from the XK resulting in a 10 per cent increase in torsional stiffness over and above the XK RS. “The best example is the work we’ve done around the structural castings, nodes,” says Hoban, “ so the front suspension mounts the ‘A’ post castings, the base of the ‘A’ posts and ‘B’ posts castings as they’re really the foundations around which the body is built.
“We measure it in frequency and degree per load as well. The frequency is also about measuring the noise paths back into the structure at a more specific point in the vehicle from NVH point of view.
“As important are the front suspension mounts and we’ve increased the lateral stiffness between those two mounts by 30 per cent over the RS and that’s important because when you couple that with suspension knuckles that are 24 per cent stiffer than the RS, it results in probably the stiffest open sports car on the market.”
However, the challenge that Jaguar has with the F-Type is that it is production constrained at Castle Bromwich not just in terms of manufacturing capacity but, also, shift patterns. This will be addressed according to JLR’s chief executive officer, Dr Ralf Speth. “Castle Bromwich is the next stage of investment for Jaguar. The first stage of the plan is to fill both plants and then long-term build all Jaguar Land Rover models in all plants.”
Which leaves plenty of scope for forthcoming models like the Audi A4/BMW 3-series challenger due in 2015. This, too, will employ aluminium structures that will be further developed for the next generation XF models.
The Volkswagen Group with its MQB, MLB and MSB strategy has already shown the way in which clever application of dimensions combined with a plug and play range of powertrains and key components such as Heating, Ventilating and Air-Conditioning (HVAC) systems can not only drive down costs to improve profitability but, also allow product planners the luxury of developing vehicles for narrow niches that might otherwise be only marginally profitable.
“Our goal is to make aluminium so affordable that it’s a no-brainer to make everything out of lightweight materials. Not only that, but to make a lightweight car for the same cost as a steel car, to minimise the cost to JLR and maximise the benefits for the customer in terms of fuel efficiency and CO2, combined with using 75% recycled aluminium by 2020,” says Mark White.
Combine that with innovative power trains and class leading styling, plus an enthusiastic work force and the prospects for Jaguar and Land Rover look more positive than ever before.