All New Volvo XC70: New six-cylinder in-line engine - two engines in one
All New Volvo XC70: New six-cylinder in-line engine - two engines in one
The all-new XC70 is powered by a 3.2-liter in-line six cylinder engine that produces 235 horsepower and 236 lb.-ft. of torque. The six-cylinder normally aspirated engine - a first for an XC70 model - offers a high-class driving experience. The main structure of this new engine (first seen in the All New Volvo S80 and the '06 MY XC90) is made of aluminium and has a larger displacement than its predecessor, with more power and greater torque.
With its advanced valve mechanism called CPS (Cam Profile Switching), the dual cam profile inlet valves can be raised to two different heights depending on engine revs and load.
In normal driving, with normal throttle activation and low engine revs, fuel consumption is minimized at the same time as there is sufficient torque for good drivability. In sportier driving under full acceleration and high revs, the engine is immensely alert to the throttle and powerful at both low and high speeds.
"In principle two-engines-in-one," explains Thomas Ahlborg, Volvo's XC70 project director. "The I6 satisfies both performance-orientated customers as well as those who prioritize driving comfort and fuel economy." For more enthusiastic driving that involves full throttle opening and high engine revs, throttle response is heightened and provides a massive thrust of power, both at low and at high speeds.
In addition, the engine features VIS (Variable Intake System) that consists of two throttle valves that adjust the volume of the inlet manifold to suit the current driving conditions and allow the engine's capacity for maximum exploitation throughout the rev range.
Mated to the engine is a six-speed automatic gearbox with Geartronic, which is designed to handle the power of the 3.2-liter engine. With Geartronic it is also possible to change gear manually.
Compact format contributes to impressive collision safety
Despite the engine's 3.2 liter displacement, it has extremely compact exterior dimensions. The complete engine package is only 1/10th of an inch longer than Volvo's five-cylinder engine. The total engine length is 25 inches.
"A compact format is a matter of safety," explains Ahlborg. "It is particularly important that the engine takes up minimal longitudinal space in the vehicle. The way we see it, a compact transversely installed engine is the best way of reducing the risk of intrusion into the passenger compartment in a collision."
The engine's compact format has been achieved by locating the ancillaries, such as the Power Assisted Steering Pump and Air Conditioning Compressor, behind the engine in the space above the gearbox. Consequently, there is no front-end drive of the ancillaries. Instead they are driven via gears by the rear end of the crankshaft. This engineering solution is known as READ - Rear End Ancillary Drive. The alternator is direct-driven and installed on the engine block. This solution means that the entire engine and transmission package takes up minimum space, particularly in the car's longitudinal direction.
By designing the drive system in the form of a small gearbox with an intermediate shaft inside the driveshaft - known as a Shaft in Shaft design - it was possible to ensure a very short package. The two shafts are driven by different gears that give them different speeds (one speed for camshaft drive and one for the ancillaries). "It's a particularly compact solution that is the result of highly advanced development work," explains Ahlborg.
Engine noise is minimized in the passenger cabin by using a vibration damper, which is integrated into the engine block of the six-cylinder engine's relatively long crankshaft. "All told, the new six-cylinder engine offers a premium experience in every respect," comments Thomas Ahlborg in referencing the engine's performance, fuel efficiency, driving comfort, as well as its sound. The fact that the engine's design also helps enhance safety isn't something the customer usually thinks about but it is naturally a key element in a Volvo product concept," he adds.