# New Engines for the Audi A6



## [email protected] (Apr 9, 2004)

Audi A6 2.7 TDI
The second representative of the latest generation of V6 TDI engines with common rail system and piezo inline injectors is set to be launched from November 2004. 
Like its big brother, which has a capacity of three litres, it makes use of the latest injection technology and consequently already undercuts the demanding EU4 emission limits, even without a diesel particulate filter.
A new crankshaft with the stroke reduced by 8.3 millimetres, new connecting rods and different pistons result in a total capacity of 2698 cc. This engine’s key performance data are a power output of 132 kW (180 bhp) in a speed range of between 3,300 and 4,250 rpm and a peak torque of 380 Nm which is available from 1,400 rpm and remains at this high level all the way up to 3,300 rpm.
The results are a spontaneous response and tremendous pulling power even from the lowest revs. The 100 km/h mark is passed after just 8.9 seconds on the way up to a top speed of 227 km/h. But it is the mid-range sprints that are the outstanding discipline of this new high-performance engine.
The pioneering common rail injection system with piezo inline injectors permits up to five separate amounts of fuel to be injected per working cycle, at an injection pressure of 1600 bar. Piezo technology enables considerably smaller and more precisely metered injection quantities. At the same time, the system reacts twice as fast as existing solenoid-valve injectors thanks to the higher speed of the injector needle. 
This effect is particularly important for the brief intervals between the – up to five – separate multiple injection processes. The fuel is injected into the combustion chamber via eight-hole nozzles. In conjunction with the combustion chamber recess, this results in excellent fuel preparation and consequently in particularly efficient combustion with extremely low emissions.
The 2.7-litre V6 TDI is also part of Audi's new range of V-engines and has a chain drive for camshafts and oil pump. The cylinder spacing in the new engine block is now 90 millimetres. This gives the engine a compact length of just 444 millimetres. The engine block is made from vermicular graphite cast iron, a successful combination of low total engine weight, high strength and good acoustic properties. This benefits not only the car's power-to-weight ratio, but also the weight distribution – two factors crucial to the superior driving dynamics of the new A6 2.7 TDI.
Other key features of the engine include four-valve-per-cylinder technology with low-friction roller cam followers, turbocharging with two intercoolers and electrical control of the variable turbine geometry. The electrical adjustment of the guide vanes is more spontaneous and more exact. Particularly at low engine speeds, this builds up the boost pressure faster and thus achieves a significantly better response.
Variable swirl flaps are likewise integrated into the intake tract. These can be used to adjust the air movement according to the prevailing engine speed and load.
All these measures result not only in high performance and an enormous torque plateau, but also in low fuel consumption, extremely low emissions and outstanding acoustics. It is especially in this latter area that the new engine undoubtedly represents the new benchmark in its class.
And thanks to its controlled and cooled exhaust-gas recirculation, the new A6 2.7 TDI remains within the limits of the strict EU4 emissions standard, which is not due to become law until 2006.
The engine's economic superiority is at least as positive as its high standard of efficiency in the reduction of emissions: overall fuel consumption is a mere 6.8 litres of diesel per 100 kilometres.
Audi A6 3.0 TDI quattro with optional diesel particulate filter
As on the Audi A8 flagship model with 3.0-litre V6 TDI, a version with the option of a diesel particulate filter is to be added to the Audi A6 range from the autumn. This version reduces particulate emissions still further. Both with and without filter, the A6 3.0 TDI quattro with 225 bhp engine not only satisfies EU4, currently the strictest emission standard in force; it is also outstanding for its combination of dynamic performance and economical fuel consumption, while displaying all the characteristics of a comfortable long-distance luxury saloon.
The "catalysed soot filter" (CSF for short) has a filter coating containing precious metals and acting in two ways: the passive regeneration process involves the slow, environment-protecting breakdown of the particulates deposited in the filter. This process takes place within a temperature range of 300 - 500 degrees and occurs continuously without any special measures being required, predominantly when the car is being driven overland and at motorway speeds. The process of active regeneration is triggered when the particulate filter has reached its maximum permitted degree of saturation. Depending on operating conditions, distances of up to 2,000 km can be covered before this takes place. A decisive advantage: due to the fact that regeneration phases are rare as a result of the generally low level of untreated emissions, the average additional fuel consumption is very low at 0.1 litres per 100 kilometres. The system requires no fuel additives at all and lasts the lifetime of the vehicle itself. 
Audi A6 2.0 TDI 
Driving pleasure and economy, refinement and environmental care: the important four-cylinder TDI version is now also available in combination with the 6-speed manual gearbox. 
The 2.0 TDI four-cylinder version with unit injector, one of the most modern engines in its class, made its debut in the executive class as a very talented all-rounder. 
Again, the particular strength of this engine is its high output and powerful torque, combined with equally impressive economy. The Audi A6 2.0 TDI is able to easily cover a range of more than 1,100 kilometres on one single tank of diesel.
A maximum output of 103 kW (140 bhp) and peak torque of 320 Nm, available all the way between 1,750 and 2,500 rpm, make this the most powerful and dynamic four-cylinder diesel featured by Audi so far. Performance on the road is correspondingly impressive: the 2.0 TDI with 6-speed manual gearbox accelerates to 100 km/h in just 10.3 seconds and continues on up rapidly to its top speed of 210 km/h.
Two other key strengths of the 2.0 TDI are low fuel consumption – 6.0 litres of diesel fuel per 100 km (overall value) – as well as compliance with the EU4 emissions standard.
And last but certainly not least, the four-cylinder unit gives the new Audi A6 a standard of smoothness and refinement which certainly befits a luxury saloon of this calibre. The balance shaft module with two shafts rotating in opposite directions, for example, helps to reduce engine vibration to an absolute minimum particularly at high engine speeds, with second-order vibrations being reduced by more than 80 percent. 
New engine/transmission versions in the Audi A6
The Audi A6 2.4 is now also available with the multitronic continuously variable automatic transmission, a transmission that combines the advantages of manual gearbox and geared automatic. Fortes typical of multitronic are smooth but very dynamic acceleration as well as convenient operation and the efficient transmission of power.
The high standard of operating convenience offered by multitronic exceeds that of a conventional converter-type automatic transmission, while in terms of dynamic performance and economy, multitronic can by all means be compared with a manual gearbox. And if drivers wish to actively choose the appropriate transmission ratio, they are able to do so conveniently by means of paddles on the steering wheel – now providing no less than seven predefined speeds.
Modified for the new Audi A6, the multitronic variator spans an even wider range of gear ratios: the overall ratio between the largest and the smallest gear transmission ratio is now 6.25, virtually ideal for such a transmission. It permits dynamic, sports-style acceleration thanks to the use of lower ratios, but also fully exploits the engine's economy potential by using the highest ratio.
A brand-new multitronic function in the Audi A6 is the starting assist function: a simple press of the brake pedal and the service brake automatically prevents the car from rolling back on a gradient. It is also released automatically as soon as the driver opens the throttle to pull away again.
With a power output of 130 kW (177 bhp) and a maximum torque of 230 Nm between 3,000 and 5,000 rpm, this new model version accelerates from 0 to 100 km/h in 9.2 seconds. It goes on to reach a top speed of 226 km/h and achieves an overall fuel consumption of 9.6 litres of premium grade fuel (95 RON) per 100 kilometres under standard conditions. 
The A6 3.2 FSI quattro with 6-speed manual gearbox is also a new addition to the range. quattro permanent four-wheel drive is a typical feature of all high-performance Audi models. It ensures excellent traction and stable cornering, and minimises the effect of propulsive forces on the car's self-steering properties. This is a precondition for a high level of dynamic stability and high cornering speeds.
A Torsen differential in the new Audi A6 – with its longitudinally installed engines – automatically ensures the optimum distribution of power between all four wheels. The name "Torsen" is a contraction of the two terms "torque" and "sensing". The Torsen differential is a self-locking worm gear.
The advantage is that the locking action is only prompted by the driveline. Yet this type of differential accommodates differences in speed when the brakes are applied and when cornering. Normally the power is split 50:50 between the two pairs of wheels, but in extreme cases 75 percent of propulsive power can be diverted to either pair. 
With a power output of 188 kW (255 bhp) and a maximum torque of 330 Nm at 3,250, the A6 3.2 FSI quattro accelerates from 0 to 100 km/h in 6.8 seconds and continues on up to a governed top speed of 250 km/h. This model’s overall fuel consumption under standard conditions is 10.9 litres of premium grade fuel 
(98 RON) per 100 kilometres.


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