Weight reduction has been an ongoing theme for Land Rover in recent years, with significant reductions for both the Land Rover Discovery and Range Rover. With the launch of the Discovery Sport, unveiled at the 2014 Paris Motor Show, Land Rover is extending the weight reduction theme with engine downsizing.
It’s the first Discovery badged vehicle in a decade not to be offered with a V6 or V8 engine. In fact, the Discovery Sport has much more in common with the Range Rover Evoque, with which it shares powertrain options and many structural components.
Although the car has been launched with the 2.2-liter four cylinder diesel, which can trace its roots back to the company’s days under Ford ownership, it’s certain that replacement engines are on the horizon, now that production of a new family of Jaguar Land Rover turbocharged 2.0-L four-cylinder Ingenium gasoline and diesel engines is due to begin in early 2015. For now the 2.2-L diesel is offered with power outputs of 150 hp (112 kW) for the eD4 and 190 hp (142 kW) for the sD4. A 2.0-L gasoline engine is also available rated at 240 hp (179 kW).
The Discovery Sport structure is based on a steel monocoque, but with a hood, roof, and tailgate formed from aluminum. A single-piece cross-vehicle magnesium beam is used, saving around 7 kg (15 lb) compared with a fabricated steel alternative. Curb weight starts from 1765 kg (3890 lb).
A new lightweight structure is just one of the technical highlights. It’s the first smaller Land Rover model to offer up to seven seats, or five plus two (5+2) seating as Land Rover describes it. To accommodate this, Land Rover has designed a new multilink rear axle.
The company claims a first in class for the hood-mounted pedestrian airbag, fitted as regular equipment, along with Autonomous Emergency Braking (AEB). Although AEB is not yet mandatory for passenger cars in Europe, it will be impossible for new models to gain a five-star Euro NCAP rating in the future if the system is not fitted.
The AEB system uses a pair of stereoscopic cameras to sense objects ahead of the vehicle up to 80 m (262 ft) ahead. The cameras are mounted near the rear-view mirror behind the windshield. “When it monitors a potential collision risk, it operates between 5 and 80 km/h,” said Cleaver. The system will give an audible warning and a visual warning in the instrument cluster or head-up display. “If the driver doesn’t react, it precharges the brakes; if the driver still doesn’t react, it automatically brakes the vehicle. Up to 35 km/h (21.7 mph), it will avoid a collision altogether and will mitigate collisions up to 80 km/h (49.7 mph).”
Four-wheel drive, using an electronically controlled Haldex center coupling, is the regular offering at launch, but this will be supplemented later in 2015 with a two-wheel-drive diesel-powered model badged eD4, with projected CO2 emissions of 119 g/km, measured on the New European Driving Cycle (NEDC).
The Haldex coupling will automatically decouple the rear differential in regular on-road driving, reducing frictional losses in the driveline. When other drive modes are selected using the Terrain Response system, the center coupling is automatically engaged. Four-wheel-drive Discovery Sports will have the choice of a ZF nine-speed automatic transmission or Getrag six-speed manual. Gasoline powered models are available with the ZF nine-speed automatic transmission.
“The main objective for us has been to develop a very compact SUV," Paul Cleaver, Discovery Sport Vehicle Program Director, told Automotive Engineering. “A key priority was not to exceed 4.6 m (15 ft) in overall length. When you look at how this car compares with other premium SUVs, it’s actually 39 mm (1.5 in) shorter than the Audi Q5, for example. If we look in the rear of the car, this is a 5+2 seater, with rear seats designed for teenagers and occasional use for adults.
“In terms of engineering, Discovery Sport is based off the Evoque platform. So the powertrain architecture, front end, transmission, driveline, all the technologies are based on Evoque, but everything from the heel board backwards is new, including the rear suspension system.
“We’ve got a new integral link rear suspension, which we have designed from scratch. The concept is the same as we use on our bigger products, the Range Rover and Range Rover Sport. We’ve selected that system to afford us the space that we needed in the rear of the car to package the seats. So all the suspension is new and given that we’ve designed it from scratch, we’ve optimized NVH (noise, vibration and harshness) and dynamics.
“We’ve taken the opportunity to optimize those components from a weight perspective. The knuckle and the lower control arms front and rear on the suspension system are hollow cast aluminum components to take weight out of the vehicle.
“So a lot of the focus on the architecture has been around the back end of the car, firstly to get that very compact stance. Proportionally we wanted the car to be the way it is from a design perspective, but then if you look at the occupant package that we’ve managed to deliver with the +2 seats and the slide-and-recline second row seats, we didn’t want to give anything away in terms of interior occupant space.”
The second row seats can slide fore and aft through 160 mm (6.3 in). With the second-row seats set in the rearmost position, occupants have 1011 mm (39.8 in) of knee room, compared with 1025 mm (40.4 in) for the Range Rover Vogue. The wheelbase is 81 mm (3.2 in) longer than the Range Rover Evoque, while the car is 91 mm (3.6 in) longer overall than the Land Rover Freelander.
Land Rover claims that the Discovery Sport is the first SUV on the market to offer an external pedestrian airbag. The airbag has a volume of 110 L (3.9 ft³) and operates at speeds between 25 and 50 km/h (16 and 31 mph). Pressure sensors are located in the front fender, connected via a pressure tube. “When the system detects enough force on the pressure tube, the airbag is deployed within 50-60 milliseconds,” said Cleaver. “The bag is deployed across the trailing edge of the bonnet and up and around the A-pillars.”Continue reading »