Audi A4 FSI with TT wheels

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The new combustion system of the Audi A4 delivers lower exhaust emissions, improved fuel economy and increased power and torque compared with an equivalent, conventionally injected engine.

With 150bhp and 200Nm of torque, the FSI saloon can reach 62mph from rest in 9.6 seconds and continue to a 135mph maximum speed, yet at the same time is capable of covering just under 40 miles per gallon of petrol (combined cycle).

This trade-off between power and economy is achieved by an advanced lightweight aluminium four-cylinder petrol engine, which is directly fuel injected to maximise efficiency. Fuel is delivered straight to the cylinders by a high-pressure common rail injection system supplied by a single-piston injection pump – rather than into the intake manifold, as is the case with most petrol engines.

This common rail technology, which has traditionally been confined to diesel units, is combined with other special features to enable the engine to operate in two 'modes'. When a high power output is required, the electronics select the homogeneous mode, which is the normal operating state for conventional indirect injection engines.

At normal cruising speeds, under part load, the engine switches to 'stratified charge' operation. In this state, the air, or 'charge', is directed extremely accurately towards the spark plug using the 'tumble' principle, created by a tumble flap within the intake manifold and a specially shaped bowl in the piston crown.

Fuel is injected only in the piston's compression phase, rather than during induction as is the norm, and is placed in the tightly controlled stream of intake air moving towards the spark plug. The combustible mixture is therefore only present in a restricted area of the combustion chamber, surrounding the spark plug, and injection takes place at a very shallow angle, minimising the potential for losses.

The new Audi A4 2.0 FSI can be ordered now for £19,565 OTR in saloon form or £20,695 OTR as an Avant.

For the best possible engine efficiency, and therefore lowest fuel consumption, ultra- low sulphur or sulphur-free fuel is recommended for use in FSI-powered models. However, the new engines are also designed to run on 98RON super unleaded or 95RON unleaded with virtually no losses in performance or economy.

The above information was taken from www.newcarnet.co.uk - please feel free to reply with your opinion on the car.