Jaguar's new S-TYPE is the company's first compact sedan since the Mark 2 and original S-Type of the 1950s and 1960s. The MY2000 car will be powered by one of two engines: the company's 209-kW (280-hp DIN), 4.0-L AJ-V8 or a new, all-aluminum, 179-kW (240-hp) (DIN), 3.0-L AJ-V6. Designed specifically for the S-TYPE and its Lincoln LS sister vehicle, the high-output AJ-V6 is jaguar's first production V6 engine. The 3.0 V6 S-TYPE with a manual transmission sprints from 0 to 97 km/h (60 mph) in 6.8 s (8.0 s for the automatic) and on to a top speed of 235 km/h (146 mph)—227 km/h (141 mph) for the automatic. The 3.0 manual also achieves an impressive average fuel economy of 27 mpg.

Jaguar's powertrain engineers worked closely with their Ford counterparts throughout the engine program. The design of the quad-cam AJ-V6, which uses a cylinder block derived from the Ford V6 modular engine, was undertaken by the same team of engineers that created jaguar's AJ-V8. Detailed design of the engine was completed by a collocated team of Jaguar and Ford engineers. Development and testing of the engine took place at jaguar's Engineering Centre at Whitley in Coventry, UK.

Jaguar says the new 60¡ vee engine shares the fundamental engineering architecture of its AJ-V8 including combustion and cooling systems, cylinder head, and valve gear. Specific similarities can be found in the all-aluminum construction; structural bedplate block design; sinter-forged, fracture-split connecting rods; four-valve-per-cylinder combustion chambers; variable camshaft timing; chain-driven, direct-acting camshafts; and precision cooling technology.

Many predictive and analytical computer-aided engineering techniques were used in developing the engine. Computational fluid dynamics was used in development of the lubrication and cooling systems. A finite-element analysis model was developed for the complete powertrain to ensure stiffness matching of each of the major engine components and transmission for improved smoothness. This model was also used to optimize the mounting of the assembled powertrain to both the vehicle and the exhaust system. Fused-deposition modeling equipment allowed swift creation and evaluation of engine components.

The AJ-V6's peak power is produced at 6800 rpm, with maximum torque of 300 N•m (221 lb•ft) at 4500 rpm. At the S-TYPE's launch, Jaguar expected the engine's power output to be among the highest of any naturally aspirated 3.0-L, six-cylinder engine on the market. Despite its high specific output of 60.3 kW/L (80.9 hp/L), the company stresses that the engine is neither peaky nor temperamental, saying the design provides throttle response similar to that of a much larger engine. The combination of a variable-geometry intake system and variable camshaft phasing helps the engine deliver at least 90% of its rated peak torque from 2500 to 6000 rpm.

At the initial design stage for the AJ-V6, it became clear that Ford's modular V6 block construction was similar to the Jaguar V8 concept and a good basis for jaguar's new V6 engine. The AJ-V6 team set about creating a block strong enough for the higher power output and suitable for rear-wheel-drive application, while maintaining the ability to be machined on the modular V6 block tooling.

Preliminary AJ-V6 Specifications for North America

Engine type 60o V6, aluminum-alloy head/block, chain-driven, 24-valve DOHC Displacement 2967 cm3 Bore x stroke 89 x 79.5 mm (3.50 x 3.13 in.) Compression ratio 10.5:1 Redline 7000 rpm Maximum power (DIN) 179 kW (240 hp) @ 6800 rpm Maximum torque (DIN) 300 N•m (221 lb•ft) @ 4500 rpm Combustion chamber Pent roof Injection system Electronic sequential port Fuel requirements Premium unleaded (Mexico - Regular unleaded)

The new cylinder heads use jaguar's patented precision cooling system and direct valve actuation through bucket tappets, which provide a compact combustion chamber and a high compression ratio of 10.5:1. The crankshaft is made of forged steel for improved refinement. Platinum-tip spark plugs are used to stretch the replacement period to 160,000 km (100,000 mi.), and the oil change interval is 16,000 km (10,000 mi.) under normal driving conditions.

Other interesting features of the new engine can be found in the systems for variable intake and camshaft timing and full-authority, electronic throttle control.

The three-stage variable-geometry intake manifold uses a compact "foldover" layout and incorporates a pair of two-position, electrically operated gate valves and long, equal-length exhaust downpipes. The valves are opened or closed by the engine management system at calibrated engine speeds to optimize intake-manifold plenum geometry for volumetric efficiency. The benefit is greater torque output over a broad engine-speed range and improved transient response.

A two-step actuator on each intake camshaft varies the relative position (advanced or retarded) as determined by the engine management system. Valve timing events—in particular, the overlap period, when both intake and exhaust valves are open—are optimized for idle smoothness, full-load performance, low exhaust emissions, and good fuel economy.

An electronic throttle system is driven by the engine management system through the multiplex network. This full-authority electronic throttle control results in smooth, refined response. The powertrain electronic controller integrates both engine and transmission functions and has a memory capacity of 1 MB.