Compact V6 motors for highest performance requirements
- The entry-level model is the 3.0 V6 naturally aspirated engine with 265 PS
- The injection model in the Aero makes 2.8 PS with its 6 V300 turbo engine
- Adaptive 6 automatic gearbox
The Saab 9-4X is powered by two compact six-cylinder engines, both equipped with state-of-the-art technology, which show the performance that is found in high-capacity engines, but with lower fuel consumption and lower emissions.
The entry-level model, the 3.0 V6 engine, features 265 PS, while the turbo-charged V6-2.6 l engine with 300 PS - as in the new 9-5 Sedan - provides propulsion in the Aero models. Both transversely mounted engines are tuned to the 6 automatic transmission with the Saab XWD four-wheel drive. ,
The machines feature electronic engine management, electronic throttle control, direct injection and four valves per cylinder that are moved by overhead, maintenance-free and chain driven camshafts. The variable valve control both inlet and outlet side allows a speed and load-dependent opening and closing of the valves. This allows for a wider torque range, higher peak power and fuel economy, and a better emissions balance.
To ensure the lowest piston friction and wear characteristics while at the same time reducing oil and fuel consumption, the cylinder walls of the motors were laser-machined to achieve an absolutely smooth surface. Oil cooling below the piston head and sodium filled exhaust valves are further measures to improve performance.
A speed-controlled engine management system is used in both machines. An optimal position of accelerator pedal, camshaft, ignition timing and turbocharger pressure at all engine loads and speeds is calculated.
3.0 V6 naturally aspirated engine
This fuel-efficient, all-aluminum engine delivers 265 PS (195 kW) at 6950 revolutions / min and delivers outstanding 302 Newtonmeter torque at 5200 revolutions / min. It accelerates the 9-4X from 0 to 100 km / h in just 9 s.
A technical feature of the engine is direct injection where the fuel is injected under high pressure directly into the combustion chamber rather than through the intake passage where it is mixed with air. This means an improved combustion and allows a very high compression ratio of 11,7, which is associated with a performance increase and lower fuel consumption at partial or full throttle. During the cold start phase, when the engine produces the most emissions, direct injection represents an improvement of up to 25%.
In addition to the aluminum construction, the engines are characterized by further weight-saving and / or noise-reducing properties: Exhaust manifold top made of a composite material instead of aluminum; integral exhaust manifold for avoiding separate exhaust sections; Composite material instead of die-cast aluminum, camshaft covers.
The 6 automatic transmission allows a wide range of shift patterns, adapted to the driver's driving style and habits, and intervenes at lightning speed when polling for maximum acceleration or power. The transmission also adjusts to the prevailing road conditions and switches back on inclines or downhill to use the engine brake on downhill. It is a dual-clutch transmission with manual sequential gear selection via rocker switch on the steering wheel.
2.8 V6 turbo.
Available exclusively in the Aero version, this all-aluminum engine features a classic 60 ° arrangement of the cylinder banks for optimum balance and ride without vibration. The engine delivers power of 300 PS (221 kW) at 5500 revolutions / min and impressive torque of 400 NM between 2000 and 5000 revolutions / min.
In practice, this is sufficient for an acceleration from 0 to 100 in 8,3 s. Like all turbocharged engines, this unit offers power delivery that features more powerful engines, but with lower fuel consumption when no powerful feed is needed, such as on relaxed highway driving.
The twin turbocharger is located centrally above the transmission and is powered by both cylinder banks. Using two intake ports, one for each cylinder bank, separates the exhaust pulses, improves gas flow, reduces energy losses, and boosts turbocharger performance. The turbo is water-cooled and uses an air-to-air charge air system to improve intake charge density.
The four main bearings receive a stable crankshaft and the steel anchoring rods are forged to improve strength and stability. The aluminum pistons have a polymer coating, the floating piston pins are cooled and are additionally lubricated via triple oil nozzles under the piston crown.
The double-walled exhaust manifolds with hydroformed stainless steel pipes improve cold start conditions by minimizing heat absorption by the exhaust and reducing emissions. Also, the air injection into each exhaust manifold for up to 30 seconds after the cold start supports the central, - switched on - main catalyst upstream pre-catalyst to reach the operating temperature as soon as possible.
For a smooth and quiet engine run, the aluminum die-cast sump was stiffened and bolted to both the gearbox and engine block to eliminate vibration points. The camshaft covers are fully insulated and consist of a composite material for effective noise reduction.
The 6 automatic transmission for this engine has an integrated electronic control module that eliminates the need for any external wiring. The transmission has an adaptive shift logic similar to the automatic transmission of the 3.0-V6i, but can also be supplied with a manual, steering-wheel-operated shift lever that complements the conventional manual shift lever.
The fuel consumption of both engines is not fixed yet.
Source / Pictures: Saab Automobile AB