Volvo S80 is known as the T-6, continuing the Volvo tradition of fast and sporty turbo-charged T-5's.

• The aim when the T-6 was developed was to combine the advantages of a relatively small engine- in terms of fuel consumption and environmental load- with the characteristics and performance of a much larger engine, in an appealing and advantageous manner.

• The turbo charging is of the parallel type- in other words, two small but efficient turbochargers are each driven by and feed three cylinders. Volvo has previously tested the system on a high-performance engine and it is now being applied in standard form.

• The T-6 engine reaches its full torque far more quickly with twin turbos compared to an engine with one large turbocharger, as there is less inertia in the blades in smaller compressors.

• The fact that the ignition sequence and the valve timing in an in-line, six-cylinder are perfectly suited to a turbo concept of this type, is clearly demonstrated by the torque curve. This was also the order of priority when the engine was developed. Outstanding torque and flexibility rather than just a high power output. It is torque that matters in everyday driving.

• The opportunity to offer so many variants is a result of the design of the modular engine. The basic RN engine concept for all the petrol engines is the same. It consists of five main parts. These main parts are all made of cast aluminum for low weight and high efficiency.

• The methods used for design and manufacture ensure very compact and rigid engines, featuring extremely low noise and vibration emissions. The high precision of the cast main engine parts makes conventional gaskets superfluous; liquid gaskets are used and the parts are then joined together with yield-point tightening bolts during final assembly.

• This basic concept can be expanded or reduced depending on the needs. In technical terms, the four-cylinder engine is more or less the same as the six-cylinder, but it has two fewer cylinders.

• Starting from the bottom, there is the oil sump, made of high-pressure, die-cast aluminum and of a new design compared with that of the N series. On engines with an oil cooler, this is integrated on the engine.

• The lower crankcase and cylinder block are also made of high-pressure, die-cast aluminum and they both form a very compact and rigid unit. Both have reinforcing ribbed structures in order to reduce panel vibration and the transmission of noise.

• In the six-cylinder engine, the crankshaft runs in seven main bearings, whereas in the

five-cylinder it runs in six.

• The crankshafts are made of forged vanadium steel. All oil channels and cooling ducts are all cast in during production and require no subsequent machining.

• The grey-iron cylinder liners in the block are also cast in during the high-pressure process. These liners offer high wear resistance and reduce the risk of leakage.

• The slots between the cylinders at the upper edge of the block are specially machined to minimize the risk of ovality in the cylinders as a result of thermal expansion. The cylinders are very narrowly spaced, giving every engine variant a small overall length.

• On top of the lower crankcase/cylinder block assembly sits the cylinder head. It is made of chill-cast aluminum to ensure a homogeneous material.

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