The Range Rover Vogue's new TDV8 diesel engine builds on learning from the widely acclaimed TDV6, used in the Discovery 3 and Range Rover Sport. Delivering substantial improvements in both performance and refinement, its maximum power is increased by more than 50 per cent, at 272 bhp/PS (200 kW), compared with the outgoing straight-six diesel's 177 bhp/PS (130 kW).

Maximum torque is an enormous 640 Nm (472 lb ft). This is maintained constantly from 2000 rpm to 2500 rpm, delivering effortless performance even at low engine speeds. Over 400 Nm of torque is available from just 1250 rpm - greater than the previous engine's maximum torque of 390 Nm (288 lb ft).
Acceleration is similarly transformed, with the 0-60 mph time down to 8.5 sec from 12.7 sec (0-100 km/h now 9.2 sec, from 13.6 sec). The improvements continue right across the speed range. In the crucial 50-70 mph acceleration range (80-110 km/h), for example, the new diesel model is about 40 per cent faster. Top speed is an electronically limited 124 mph (200 km/h), up from 111 mph (179 km/h).

Twin variable nozzle turbochargers contribute to the huge torque of the V8 diesel, as does the relatively low 17.3:1 compression ratio. The 32-valve engine configuration allows for smooth high-revving, assisting performance and on-road refinement.

The engine exceeds EU4 emissions standards and fuel consumption is impressively low considering the performance: combined average fuel economy is 25.1 mpg (11.3 litres/100 km). This is comparable to that of many petrol saloon cars, in a vehicle that has the capability to cruise motorways, climb mountains, cross rivers, carry five adults in ultimate comfort plus an enormous amount of luggage, and has one of the highest permissible towing weights of any vehicle.

Although sharing many technologies with the TDV6, the 3.6-litre TDV8 has been designed from the outset to meet the refinement, torque characteristics and off-road needs of the Range Rover Vogue. It is not just a V6 with two extra cylinders. For example, the V6 has a bank angle of 60 degrees, while the V8 has 90 degrees - the best configuration for a V8's balance and refinement.

As with the TDV6, the TDV8 uses a revolutionary Compacted Graphite Iron (CGI) block, which has much higher tensile strength than 'standard grey' cast iron, better fatigue strength than aluminium, and extraordinary stiffness. Its overall advantages in weight and strength mean the block can be lighter and smaller than those of rivals, making it astonishingly compact for such a large-capacity engine.

The block's outstanding stiffness is a major factor in the refinement of the engine. The TDV8 is one of the world's quietest and smoothest diesels, as well as one of the mightiest. Heads are cast in aluminium. The overhead camshafts - two per cylinder bank - are hollow to reduce weight, and actuate the 32 valves through roller-finger followers and hydraulic lash adjusters. The intake camshaft is driven by a simplex bush chain, the exhaust camshaft by near-silent gearwheels. The intake manifold - made from lightweight injection moulding - and cylinder heads employ Land Rover's intake port deactivation technology, to optimise swirl across the full engine speed range.

The new TDV8 is designed not just for day-to-day road driving and high-speed motorway or autobahn cruising, but also for river wading, dust, mud and the steep angles necessary for class-leading off-road capability. As with all Land Rover products, the new Range Rover Vogue TDV8 must be able to drive through 45-degree gradients and traverse 35-degree side slopes, as well as wade through water 500 mm deep.

The 90-degree V8 configuration means the twin turbochargers are sited low in the engine. At extreme angles, there is a risk that either turbo may be below the sump level, restricting oil flow. So a new, patent pending, vacuum lubrication system has been developed to ensure full flow of oil at all times to the critical turbochargers, even on the most severe side slopes. No other turbo V8 has anything like the all-terrain versatility of the Range Rover Vogue's new engine.

The variable nozzle turbochargers - one per cylinder bank - have small turbine wheels, for excellent response. Their variable nozzle design boosts not only response, but also low-end torque and top-end power. No wastegate is necessary, improving refinement and boosting the progressive driving characteristics of the engine.

Common-rail injection technology improves refinement, power and economy. Fuel is injected at up to 1700 bar (more than 24,000 psi), about 30 per cent higher than in previous-generation common-rail fuel systems. Incredibly accurate Piezo injectors provide highly efficient combustion, very low particulate emissions and instant power on demand. They also reduce combustion noise, improving refinement.

Despite the phenomenal performance, this is one of the world's quietest diesels. Noise, at both idle and full load, is extremely low.

"Compared with the outgoing Range Rover Vogue diesel, the new engine is up to 75 per cent quieter, a huge improvement," says Al Kammerer, product development director for Land Rover. "In both qualitative and quantitative measures, the new diesel is very similar to the V8 petrol engine - a tremendous achievement."

The noise levels are so low that Land Rover engineers had to target other sources of engine noise normally masked by combustion noise. Extraneous sounds are dampened by a comprehensive acoustic system, including a glass-reinforced nylon engine cover and sound-deadening rubber-mounted covers encapsulating the fuel injectors, to ensure that injection noise goes unnoticed.

Given the TDV8's exceptional standards of performance and refinement, it would be easy for people to mistake it for a petrol engine. So Land Rover has developed a new, patented device for the TDV8 fuel filler neck, to avoid the risk of inadvertent fuelling with petrol.

The new TDV8 diesel engine is matched to the latest-generation ZF six-speed automatic electronically controlled transmission, which offers extra smoothness and response. The CommandShift facility allows for manual gearchanges, improving the dynamic nature of the driving experience when required. Low-range is also provided, for extreme off-roading and heavy-duty towing.

Both the new gearbox and transfer box have a wider ratio spread than the outgoing units. Together, these provide for a 12 per cent lower first gear, giving better off-road control and power, while the top gear is now 28 per cent higher, to consolidate the benefits of the new engine's excellent refinement and economy.

This latest Land Rover diesel engine was developed specifically for Range Rover Vogue, jointly by Land Rover and Ford engineers. It is built at Ford Motor Company's high-tech diesel engine facility in Dagenham, England.