The Series II Land Rover Discovery was long over-due for replacement. Although still a capable and popular vehicle, its chassis, coil-spring suspension and beam-axle layout had changed very little since the launch of the original Discovery in 1989. In turn, that vehicle used essentially the same underpinnings as the original Range Rover, launched in 1970. The Land Rover Discovery II was beginning to lose sales to more sophisticated 'working' 4x4 vehicles from Japan ,such as the Toyota Land Cruiser and Mitsubishi Shogun and 'sports' 4x4s from Europe ,such as the BMW X5 and Mercedes-Benz M-Class. A replacement for the Land Rover Discovery 11 vehicle had been planned for many years, but the project had been delayed many times due to the break up of the Rover Group in 2000 and the need to replace the Range Rover in 2001. The Land Rover Discovery 3 was an entirely new design, sharing not a single component with the outgoing model.Its styling is still traditional Land Rover, with function dictating the look, rather than fashion, and with lots of horizontal and vertical lines. It retains the key features of the Discovery, such as the stepped roofline and steeply-raked windscreen. The LR3 name was chosen for North American markets due to negative quality associations with the Discovery name and a preference in the American market for alpha-numeric model designations . Construction wise, Land Rover developed an all-new method which they called Integrated Body Frame . The previous Land Rover Discovery models had used a traditional, strong ladder-frame chassis. Whilst being specifically designed for off-road use, ladder-frame chassis' are heavy and detract from the on-road handling of the vehicle. Monocoque vehicles are more rigid, giving improved high-speed handling, but can be damaged by the stresses involved in heavy off-road use. In the IBF the body, the engine bay and passenger compartment is built as a monocoque, which is mated to a basic ladder-chassis holding the gearbox and suspension. It claimed to combine the virtues of both systems, but does make the Land Rover Discovery 3 uncommonly heavy for its size stunting on-road performance and off-road agility, especially in soft ground such as sand. This was one of the reasons that the new Discovery became the first Land Rover to be offered with a rear locking differential. Another big change was the fitting of full independent suspension (FIS). Like the Series III Range Rover, this was an air suspension system, which allowed the ride-height of the vehicle to be altered by simply pumping up or deflating the air bags. The vehicle can be raised to provide ground clearance when off-road, but lowered at high speeds to improve handling. FIS had been seen as inferior to the older beam-axle when off-road due to its tendency to make the vehicle bottom out. Land Rover developed 'cross-linked' air suspension to solve this problem- when needed, the suspension mimics the action of a beam axle (as one wheel drops, the other rises). Further more, if the chassis of the vehicle contacts the ground when the suspension was at its 'off road' height, the system senses the reduction in load on the air springs and raises the vehicle an extra inch. In the UK and European markets, a coil-spring independent suspension system was offered on the base model. This model was unique in the range by having only 5 seats and only being available with the 2.7 litre diesel engine. This model Land Rover lacked the Terrain Response system. All this was designed to make the new vehicle suitable for a changing 4x4 market. Ultimate off-road ability was becoming less important compared to refined on-road manners. Land Rover were determined that the Discovery 3 would retain the brand's reputation as a top-performing off-road vehicle, whilst also being a good road car. Whilst the Discovery 3 was not as good in the handling stakes as some of the competition, it was much improved over the previous models and its off-road credentials remained intact. The engines used in the Discovery 3 were all taken from Land Rover's sister company, Jaguar. A PSA Peugeot-developed 2.7 litre, 195 hp (145 kW) V6 diesel engine was intended to be the biggest seller in Europe. For the US-market and as the high-performance option elsewhere, a 4.4 litre petrol V8 of 300 hp was chosen. A 216 hp 4.0 litre SOHC V6 petrol engine taken from the Ford stable was available in North America and Australia. Before launch, there were rumours that Land Rover may introduce the diesel unit to the American market, but the use of high-sulphur diesel fuel there, for which the TdV6 is not designed, made this fitment unlikely. The gearboxes on the Land Rover Discovery 3 were also all-new. For the diesel engine, a 6-speed manual gearbox was standard. As an option, and as standard on the V8 engine, a 6-speed automatic transmission was available. Both came with a 2-speed transfer box and permanent 4-wheel-drive. A computer controlled progressively locking central differential ensured traction was retained in tough conditions. A similar differential was available on the rear axle to aid traction. The Discovery 3 was fitted with Land Rover's full armoury of electronic traction control systems. Hill Descent Control prevented vehicle 'runaways' when descending steep gradients and 4-wheel Electronic Traction Control prevented wheel spin in low-traction conditions. An on-road system, Dynamic Stability Control prevented skidding when steering and braking at speed.