The new year brings new opportunities at Jaguar Land Rover, as the company looks to make an impact in the ferociously competitive premium mid-size car segment with the arrival of the XE. The new sports saloon, which goes on sale in the spring, will go up against top sellers like the BMW 3 Series, Audi A4 and Mercedes-Benz C-Class.
The launch of the XE is a watershed moment for the historic British carmaker, with the executive segment expected to grow from 1.55 million to 1.72 million sales annually worldwide between now and 2020. If JLR can grab even a small piece of the pie, it would deliver a dramatic rise in production numbers for the marque.
In anticipation, JLR has invested a colossal £1.5 billion at its Solihull plant, with the construction of new body stamping and final assembly facilities, creating 1,700 jobs. But it isn’t just finances that are at stake. Reputation issues will also come into play: while under Ford ownership, Jaguar tried and failed to force its way into the mid-size segment with the launch of the X-Type, which was criticised in many quarters for sharing components with the distinctly unglamorous Mondeo. This time around with the XE, it simply has to get things right.
Nick Miller, XE vehicle programme director, says the importance of the new car cannot be overstated. “It’s a huge opportunity for us,” he says. “But it’s a ruthless segment, for sure, and there has been a lot of pressure on the team here to get things right. It has really focused the mind, and we have had to work hard to get the perfect balance between manufacturability, feasibility and competitiveness.”
While the X-Type relied heavily on legacy technology, this time around Jaguar’s engineers have been in the fortunate position of creating the XE from a blank sheet of paper. The result, at first glance, is a car that very much looks the part. The rear-drive XE is the only vehicle in its class to use an aluminium-intensive monocoque, while boasting advanced technology such as double wishbone front suspension and an integral link rear axle.
The XE is the first Jaguar to be fitted with the Ingenium diesel engine from JLR’s new Wolverhampton plant, enabling it to claim impressive fuel consumption and emissions figures of 75mpg and 99g/km CO2. The XE certainly looks a match for its established rivals.
Miller is excited by its potential. He says: “Jaguar has been in this segment before and pulled out at a certain point. Now we’re going back into it again and we are approaching it very differently.
“Previously we adopted a platform, which people made their own judgement on. This time we have started with a clean sheet of paper. The car has got nothing carried over. It is all new. That gave our engineers a unique opportunity to do everything they wanted.”
Chassis considerations: The XE is underpinned by a light, stiff body structure for ride comfort and driving dynamics
It is no surprise to see that Jaguar has chosen aluminium for the core construction, having introduced the material on the XJ in 2003 and on the XK, the current XJ and the F-Type. What’s different with the XE is the amount of aluminium being used – 75% content by surface area, creating a structure that Miller believes offers unrivalled low weight, with high strength and high levels of torsional stiffness.
The XE is the first model designed using Jaguar’s all-new modular vehicle architecture. This structure will underpin a range of – probably larger – new models in a number of different segments, and is engineered to use a mix of materials, including aluminium of different grades, high-strength steel and magnesium.
In the mix are high-strength aluminium alloys, including AC300 and AC600 grades, which are used in areas such as the A-pillars, front and rear crash structures, and the cant rail. The B-pillars are high-strength aluminium reinforced with ultra-high strength steel, with a layer of high-density foam between.
“The base technology is the same, fundamentally, that we introduced in 2003 with the XJ,” says Miller. “What we have done is significantly ramp up the amount of aluminium which is high-strength, versus the more conventional grades. On the original XJ it was 30% high-strength, 70% conventional. Now it’s 70% high-strength, 30% conventional. That’s one of the big changes regarding the use of material on this car.”
Specifically, the aluminium architecture is based around a common core structure extending from the front suspension to the front of the rear seat squab. High-strength steel is used in the rear underbody and door intrusion beams, providing a stiff mounting for the rear axle, while enhancing side impact performance and helping to deliver the best weight distribution.
The front shock towers, mounting the suspension dampers, are made from high-pressure, die-cast aluminium alloy. The front end carrier and cross-car beam behind the dash are made from cast magnesium. The bonnet and fenders are aluminium, the doors and boot lid are in steel, again helping with weight distribution.
Use of high-strength aluminium alloys for the body sides has made it possible to reduce panel thickness from 1.5mm gauge to 1.1mm. This saves weight without compromising strength, says Jaguar.
“The car is not 100% aluminium,” says Miller. “There’s steel in the rear floor area, and steel for the side intrusion beams. What that gives us is very stiff points on the car to bolt the rear suspension to. It also gives us ideal 50/50 weight distribution from front to rear, which is a big part of getting that agile feel to the car. And the use of some steel does help with cost too.”
Detailed consideration has been given to joining techniques on the XE. As far back as 2003, Jaguar replaced spot welds with a combination of self-piercing rivets and structural adhesives – a technique proven in aircraft production. This enabled the design of joints combining strength, stiffness and durability.
Another advantage – and one extremely difficult to realise with welding processes – is compatibility with dissimilar materials. But to prevent any risk of galvanic corrosion between steel and aluminium panels, the XE’s monocoque benefits from five layers of protection between the two materials. The first is a protective coating of zinc on the steel parts. The joints are filled with structural adhesive and then the body is e-coated. Seam sealer is applied, and then, finally, paint is added for finishing.
Miller says the risk of galvanic corrosion was uppermost in his engineers’ minds. “The design of the joints is very detailed, so the different metals don’t actually touch,” he says. “There are multiple elements to guaranteeing the integrity. We’ve been very conscious of it throughout, and have worked closely with manufacturing and engineering colleagues. All the required controls are in place.”
Drive time: Front suspension mounting points enable efficient packaging of the spring and damper assembly
As for the chassis, camber stiffness was an important consideration from the outset. This attribute – the resistance to lateral load when the car is cornering – is crucial to steering feel. To keep unsprung mass to a minimum, the XE features forged aluminium knuckles made from cast blanks using a patented production process. Further weight savings come from the tubular anti-roll bars and springs made from stiffer, narrower-gauge steel.
Front suspension geometry was optimised from the outset to suit all-wheel drive and rear-wheel drive configurations. The suspension mounting points enable efficient packaging of the spring and damper assembly – essential to achieving the low bonnet height fundamental to the XE’s sleek styling.
Miller says Jaguar evaluated conventional multilink suspensions that are the class standard, but it felt that these could not deliver the required dynamic attributes. So the solution was the integral link rear suspension: a technology usually found only in larger, more expensive vehicles, and one that Miller says will deliver an exceptional combination of lateral and longitudinal stiffness. The front suspension, meanwhile, is of a double-wishbone design.
“It’s all about producing an agile, responsive car with good steering feel,” says Miller. “Some of our competitors employ various elements on their suspension systems but nobody employs all of them. It gives us the flexibility to use this architecture in other products that are coming up within our portfolio.”
Another technology advance on the XE is the use of electric power-assisted steering (EPAS). Up until now, hydraulics have provided power assistance on Jaguar vehicles, with its engineers unconvinced by the maturity of EPAS systems. But tireless refinement of both the hardware and the control software has led to the development of an EPAS system that Miller says meets all of the XE’s requirements.
The technology has been refined to reduce backlash and friction, while control algorithms can account for changes in the ambient temperature, ensuring consistent steering feel whatever the weather conditions. The EPAS also features speed-dependent assistance and damping, which varies subtly with the rate with which steering lock is applied, and there is an automatic compensation functionality for changes in road camber.
Miller says: “EPAS has been around for a while now, but we’ve always been reluctant to bring the technology on to a Jaguar because of the disadvantages associated with it. There were a lot of problems around the inherent friction in the whole set-up.
“But our software is so intelligent that it compensates for the friction. Also, because it’s a software-based technology, EPAS is incredibly easy to fine-tune, whereas with hydraulics any changes meant alteration to the piping, which took a lot of time.”
There’s an efficiency advantage to it, too, he says. With EPAS, there is no need for a hydraulic pump to be fitted, and that weight and parasitic loss reduction helps to cut the XE’s CO2 emissions by 3% and 2% from petrol and diesel models respectively.
The engines for the XE are a major diversion, in that they are the first from the new Ingenium family built at JLR’s new £500 million plant in Wolverhampton. Miller says the new facility gives Jaguar complete control of its own engine design, rather than sourcing them from other OEMs.
The XE is powered by a range of four- and six-cylinder petrol and diesel engines, with diesel being introduced first. All engines have direct injection, variable valve timing and stop-start systems, along with regenerative charging. Power is sent to the rear wheels through six-speed manual and eight-speed automatic transmissions.
In terms of the development process for Ingenium, Miller again refers to the benefits of a ‘clean sheet of paper approach’, enabling engineers to deliver a diesel engine that has 17% less internal friction than the unit it replaces. This has been achieved using roller bearings on the camshaft and balancer shaft; switchable piston cooling jets that are turned off when not required; and computer-controlled oil and coolant pumps which only deliver the required pressure and flow demanded by the engine.
The engine also features a simplified low-friction camshaft drive system, and the cylinder bore is offset by 12mm from the crankshaft to minimise the friction between the piston rings and cylinder wall.
In terms of performance, the 2-litre 163 PS engine achieves peak torque of 380Nm from 1,750rpm. To deliver this, features include the latest generation of variable geometry turbocharger, a Bosch commonrail fuel injection system, and variable exhaust camshaft timing. The result is low emissions without compromising peak performance.
Refinement is delivered through the use of a stiff lightweight alloy structure. Solenoid injectors are acoustically damped to avoid injector “tick”, while a balancer shaft system reduces engine vibration, driven by gears with anti-backlash features to prevent gear noise. There are acoustically treated engine covers on the camshaft cover, cylinder block and sump, and an oval fuel injection pump drive sprocket reduces timing chain noise.
“It’s a modular engine in terms of the design of the cylinders and the dimensions,” says Miller. “We’re starting with four cylinders, but we also have the ability to go with more or less. There’s a lot of elements that are common between the diesel and the petrol.”
Inside the car, another aspect of the XE that excites Miller is its connectivity. The fascia features an eight-inch screen that acts as the heart of the all-new infotainment system, operated by touch or voice control. Jaguar has developed a range of apps that allow an iOS or Android smartphone to be used to perform tasks like check fuel levels and to remotely unlock and lock the doors to allow, say, access for a family member.
Miller says that the time, money and effort JLR now spends on connectivity is an indication of just how important it has become. “Some people might think that these technologies are frivolous – but actually a lot of people want them,” he says.
“If you don’t have such capabilities then you run the risk of not being seen as a technology leader. We have developed an architecture that can be evolved over time on a common base of hardware with just software upgrades. Our ability to respond to the technological rate of change is much improved by this architecture,” he says
Big spend on machinery Production of the XE has required £1.5 billion investment at Jaguar’s Solihull site and the creation of 1,700 jobs. A new bodyshop, the size of 10 football pitches, contains 613 robots and nearly 300 rivet-gun positions. One of the big innovations here is the use of trunnions – six-sided jigs that will hold the body side and rotate it quickly while rivets are applied.
Next door, the even larger trim and final assembly hall, which has the flexibility to produce both Jaguar XE and Range Rover Sport, stretches for hundreds of metres in length, featuring more than 200 main line assembly stations and around 100 sub-assembly points.
The first batches of pre-production XE cars were produced at the end of last year for testing purposes, and the facilities are now primed and ready for full production cycles to kick in.
Joe McNamara is lean manufacturing manager at Solihull. His team has worked closely with the designers and engineers on the XE programme for the past two years and he can’t wait for the production lines to start rolling. “I’m proud of the way that the upfront manufacturing team has been able to assist the likes of Nick Miller and his team in delivering such a great car,” says McNamara.
“The car is beautiful and it is made out of aluminium. That takes a lot of work. The mixed-metal joints, for instance, was a feasibility issue that the team in the bodyshop worked through to find solutions. We’ve got two fantastic new facilities – the bodyshop and the trim and final facility – and a host of technologies to excite customers. They all need to be pieced together, assembled and tested in our new manufacturing facility. We’re looking forward to the opportunity to deliver the very best quality.”
McNamara has also been responsible for the recruitment process at Solihull, which has been a test in itself. He has added 1,700 staff in less than a year, and they all need to be trained to the requisite standard. He says: “Among that figure is around 100 employees who are ex-servicemen and women – we actively recruited them from people leaving the armed forces. We are finding their skills and experience very useful. They are a vibrant group that have come together to share their experiences with us and they are geared up to make the XE a great success.
“They come from a disciplined background, they understand what it takes to deliver projects and get the job done – often going above and beyond in terms of time commitments. They have fitted in very well. Coming from outside the car industry, they bring a fresh perspective, allowing us to look at our business a bit differently.”
McNamara says that skills shortages have been an issue at Solihull, but that he expects to fill all vacancies. “The finishing line is in sight now in terms of recruitment,” he says. “I’m still reviewing it once a month, but in terms of engineers and maintenance people we are almost there."