the new audi 3 l v6-tdi engine

COVER STORY Audi 3 l V6-TDI Engine

2 MTZ worldwide 7-8/2004 Volume 65

With the 3 l V6-TDI, Audi has introduced the first 6-cylinder diesel engine from the newAudi family of V-engines. It has a third-generation piezo common rail injection system and

develops a maximum power output of 171 kW at 4000/minand a torque of 450 Nm at an engine speed as low as1400/min. Both the Audi A8 and the new Audi A6 are ex-cellently motorised with the 3 l V6-TDI and convince driversby virtue of their spontaneity and refinement.

1 Introduction

Series production of the first Audi TDI en-gine, then with 5 cylinders and a displace-ment of 2.5 litres, began as long ago as 1989.1997 saw the introduction of the world’sfirst 4-valve V6-TDI engine with 2.5 litresdisplacement; the 3.3 l V8-TDI was derivedfrom it and introduced in 1999 [1, 2].

In 2003 Audi launched a new V-enginefamily in the diesel sector with the 4l V8-TDI, which retained cylinder centres 88 mmapart. The new 3 l V6-TDI is another mem-ber of this family, now with cylinder cen-tres of 90 mm.

Each of the TDI engines confronted thedeveloping engineers with difficult tasksdue to high mechanical loads and the so-phisticated combustion process. Due to theincreased power density and more strin-gent emission limits, new technologies had

to be introduced on the Audi 3 l V6-TDI en-gine in order to achieve all the develop-ment targets. The present article will dealwith these innovations.

Development work in the thermody-namic area and on the combustion processwill be described in a subsequent article.

2 Main Development Priorities

When the specification was compiled, therewere three major requirements:■ Compatibility with Audi’s orientation asa sporty brand, i.e., high performance andhigh torque ■ Realization of Audi V-engine strategycriteria■ Compliance with EU IV emission limitsby means of internal engine measures.

The decisive development targets werederived from this, Figure 1. Superimposed

By Christoph Anton,

Manfred Bach,

Richard Bauder,

Günther Franzke,

Wolfgang Hatz,

Henning Hoffmann and

Salvador Ribes-Navarro

Der neue 3-l-V6-TDI-Motor von Audi

Teil 1: Konstruktion und Mechanik

You will find the figures mentioned in this article in the German issue of MTZ 7-8/2004 beginning on page 518.

The New Audi 3 l V6-TDI EnginePart 1: Design and Mechanical Features

3MTZ worldwide 7-8/2004 Volume 65

on them are the characteristics of the V-en-gine family, that is to say short compactconstruction and maintenance-free chaindrives on the transmission side of the en-gine.

The technical data and main dimensionsare summarized in the Table.

3 Description of the Engine

The 3 l V6-TDI engine is an almost entirelynew design, with only a few individualcomponents adopted from the 2.5l V6-TDI.The main technical innovations, thechanges compared to its predecessor andtheir implementation are described be-low.

3.1 Chain DrivesThe Audi quattro driveline concept com-bined with Audi vehicle design calls for anextremely compact engine. The engineerswere only able to realise this with an inno-vative four-chain drive layout on the trans-mission side of the engine, Figure 2.

There are 4 chains on two levels, one be-hind the other. This arrangement allowsthe valve gear of two cylinder banks, the oilpump and the balancer shaft in the V of theengine to be driven by four single sleeve-type chains. It is this arrangement thatmainly contributes to the engine’s shortoverall length of only 444 mm.

The basic drive A, which is identical onall Audi V-engines, drives the two cylinderhead drives B and C via 2 intermediategears. From there the inlet camshafts aredriven, and spur gears within the cylinderheads transfer the drive torque to the ex-haust camshafts.

The intermediate timing gears providethe necessary reduction ratio of 1:2, so thatthe camshaft chain sprockets can be of suit-ably small diameter. This has positive ef-fects on the overall width and height of thecomplete engine.

Drive D on the Audi V-engine family isused on the 4l V8-TDI to drive all acces-sories except for the alternator and air-con-ditioning compressor [3], but on the 3 l V6-TDI only drives the oil pump and the bal-ancer shaft.

The timing gear drive sprockets, beingclose to the flywheel, are immediately adja-cent to the crankshaft’s torsional vibrationnode. In contrast to the conventionalarrangement at the front end of the engine,this helps to reduce the torsional vibrationthat would otherwise excite the chain driveand cause dynamic chain stress.

In addition the modular design of thechain drives creates high synergy effectswith the 4l V8-TDI and the spark-ignitionengines in the Audi V-engine family.

3.1.1 Measurements for ChainDrive Assessment To assess and optimise the dynamics of thechain drive, extensive functional analyseswere carried out.

In a first step, the cyclic irregularities ofthe chain drive’s components (crankshaft,intermediate timing gears and camshafts),the chain tensioner supply pressures, thepressure values in the high-pressure cham-bers of the chain tensioners and tensionertravel were measured.

The results obtained in this way servedamong other things as input variables for aspecific calculation model, which wasmade more precise by calibration with thereal measuring values. Based on the resultsof this simulation, the highest chain forceswere anticipated in drive B, since it is herethat the fluctuating moments of the com-mon rail high-pressure pump, which is dri-ven from the inlet camshaft of the leftcylinder bank, are introduced into the chaindrive.

In the course of further development, di-rect chain force measurements were there-fore performed, in particular at the drive Bchain subject to the most severe loads.These measurements helped to quantifythe maximum forces actually occurring.

Chain force measurement was carriedout by attaching four strain gauges to twoopposite external plates of the chain. Thetransmission of signals and power supplyto this measuring unit were realised bymeans of a specially developed telemetryunit which was attached to a further exter-nal plate of the chain.

The telemetry unit was attached at anadequate distance from the actual measur-ing unit, so that measurements were notfalsified by the centrifugal force exerted bythe transmitter on the chain. To receive themeasured signals and supply energy to thetelemetry unit, an aerial board correspond-ing to the chain track was positioned infront of the drive to be measured. The engi-neers took care to maintain a very small,uniform distance between aerial andtelemetry unit to ensure faultless datatransmission. The relevant position of themeasuring unit during chain rotation wasdetermined by a trigger signal for eachchain rotation. With this it was possible toallocate the chain forces to the various ar-eas of chain rotation (tensioned and slackruns, chain sprockets) and quantify themaccordingly, Figure 3.

Knowledge of the maximum forces inchain drive B and the need to satisfy thehigh safety values required by Audi for life-time components led to a chain with in-creased dynamic strength being developedin cooperation with IWIS.

Compared to conventional chains thischain is notable in particular for its widerinner plates and thus larger chain pivot ar-eas, Figure 4. This chain enabled the strin-gent requirements imposed on a single-runchain by this concept structure to be reli-ably met.

The lifetime capability of the entirechain drive was proved by various test rigand vehicle endurance test runs.

3.2 Crankcase and MainBearing AssemblyTo comply with requirements for the over-all engine as defined in the specifications, acrankcase and engine block with a 90°V an-gle which is completely new comparedwith the 2.5l V6-TDI was developed, Figure5.

The cylinder spacing was enlarged from88 to 90 mm centres in order to obtain abore diameter of 83 mm.

In view of this and the peak cylinderpressure of 180 bar, the 2.5l V6-TDI’s GJL 250mod. material could no longer be used [4].The FEM calculation showed that despite avery stable main bearing frame made ofGJS 600 spherical graphite cast iron, thecrankcase had to be made of GJV 450. Thistop-quality material permits a very thin-walled construction, so that compared withthe earlier engine block 7 kg of weight weresaved despite the larger displacement.

In close cooperation with the foundrythe entire unmachined casting concept wasoptimised for uniform wall thickness, goodcastability, satisfactory sand removal and asimple, process-reliable core structure.

To improve engine acoustics and to keepvibration excitation in the main bearingarea away effectively from the sump, thelatter is shaped to surround the main bear-ing frame and bolted to the apron of thecrankcase, which is split at the crankshaftcentre line. Furthermore, the balancer shaftis no longer located in the sump as on theprevious engine, but has been moved to theinner V of the engine block.

The open chaincase is part of the castingat the transmission end of the block.

In order to obtain the required finish onthe cylinder walls, the UV-photon exposureprocess was developed to series maturity:

In a first step the cylinder walls are sub-ject to pre-treatment with a 3-step diamondhoning tool. After this, a pulsed laser startsto melt the top layer of the finely structuredsurface. This removes the metal outer sur-face, and the graphite deposits in the cast-ing matrix are then eroded by heat, Figure6.

The cylinder wall surface is nitrided by abrief but severe local increase in the partialpressure of the atmospheric nitrogen at the



melt, resulting in a ductile, wear-resistantcylinder wall.

Heat erosion of the graphite deposits en-sures a very low but adequate oil retentionvolume on an otherwise very smooth sur-face.

Functionality in terms of oil consump-tion, reduction of frictional losses and long-term wear resistance is at such a high levelthat the engineers have been able to signif-icantly reduce the titanium content of theengine block alloy which was so far neces-sary for tribological reasons. This has re-sulted in cost reductions when machiningthe engine block.

3.4 Piston, Crankshaft DriveComponents and Balancer ShaftCompared with the most powerful previ-ous version of the 2.5l V6-TDI engine [4], thepistons and crankshaft drive componentsof the new 3 l V6-TDI have to endure a gasforce approx. 20% higher with a cylinderoutput increased by approx. 30 %. Outputper litre has risen by approx 8 %.

This significantly higher load on the pis-tons called for substantial changes in thesmall-end bearing area. The width of theupper conrod eye was increased from 22 to24 mm and piston pin diameter from 26 to30 mm. The big end of the conrod, which isdiagonally split for engine assembly rea-sons, is of trapezoidal pattern with an incli-nation of 3 degrees. This design proved tooffer the best compromise between pistonstrength, piston movement pattern andsmall-end bearing wear.

The pistons are made as before from ahighly heat-resistant aluminium alloy andcontain a stress- and position-optimisedcooling channel around the central com-bustion chamber bowl. The compressionheight is 46.3 mm. The piston rings havebeen modified to match the change in thecylinder wall, with the result that oil con-sumption, particularly during the running-in phase, is again lower than on the previ-ous engine.

The crankshaft is a 42 CrMoS4 forging. For reasons of strength, the crankpin di-

ameter was increased from 58 to 60 mm.The crankshaft is induction hardened at themain and crankpin bearing journals. In or-der to maintain uniform firing intervals,the crankshaft is of 30-degree split-pin con-struction. The thrust shoulders which lo-cate the big ends of the three pairs of con-rods are for the first time of uninterruptedall-round pattern. This measure improvesconrod and piston guidance and con-tributes to the engine’s excellent overallacoustic refinement.

The crankshaft runs in four main bear-ings. The lower main bearing shells are rat-

ed to withstand more severe loads thanthose used in the previous engine.

The balancer shaft to counteract mo-ments of the first order is located in the V ofthe engine and runs at crankshaft speedbut in the opposite direction. The balanceweights are sintered and bolted to a shaftthat runs in two bearings. For reasons ofspace, the degree of imbalance eliminatedby the shaft is only 96.5 %, but this is suffi-cient to avoid engine vibration.

3.5 Cylinder HeadThe 3 l V6-TDI engine’s cylinder heads areof entirely new design, with the followingdevelopment priorities taken into consider-ation:■ Cylinder centres 90 mm■ Rated for an ignition pressure of 180 bar■ Crossflow cooling■ Inlet port configured for switchableswirl effect■ Injector located centrally on the axis ofthe cylinder bore■ Preheat plug on the inlet side■ Chaincase cast in at the transmissionend■ Processing on existing machine tools.

In contrast to the 2.5l V6-TDI enginewith its 88 mm cylinder centres, the addi-tion of 2 millimetres in conjunction withthe bore of 83 mm has permitted larger in-let and exhaust valves to be installed andalso ensures the necessary cooling of thecombustion chamber plate between thevalves, Figure 7.

The cylinder head is rated for an ignitionpressure of 180 bar, which also provides thepotential for higher power outputs andmore stringent exhaust emission limits inthe future. For reasons of rigidity, continu-ous transverse partitions were introducedinto the cooling jacket between the cylin-der head bolts, this being possible since thecrossflow principle is used.

The coolant enters the cylinder headfrom the cylinder block at the hotter, ex-haust side of the engine, then flows acrossthe cylinder head and back into the cylinderblock on the inlet side of the cylinder head.

The cooling jacket guides the main flowdirectly between the exhaust ports. Thecoolant flow at the edge of the cylinder isguided towards the centre of the combus-tion chamber plate so that cooling at thecentre of the cylinder is improved, Figure 8.

Despite the high specific output of thenew 3 l V6-TDI engine, the additional rein-forcing and cooling measures enable thematerial used for the cast cylinder heads ofthe 2.5l V6-TDI engine, namely AISi10Mg(Cu), to be retained.

The strength of the combustion cham-ber plate was optimised in a series of stages

with the aid of FEM computations. The in-troduction of additional supports in thisarea enabled the desired level of rigidity tobe achieved.

The design of the inlet ports had to takeinto account the need for the largest possi-ble swirl spectrum to be achieved by vary-ing the flow pattern in one port only. Thespiral port was therefore given a circularentry cross-section, so that a flap controlsystem with a minimum gap width couldbe installed in the intake pipe. Dependingon requirements, this arrangement permitsa swirl of between 0.4 and 1.4 according toTippelmann to be achieved.

The camshaft bearing caps are in theform of a closed bearing frame, thus per-mitting a simple rocker cover design with aflat sealing face.

The injectors are attached by means ofspring claws with the position determinedby a dihedron on the claw. Smaller coversin the main rocker cover are provided topermit dismantling.

The camshafts have been designed totake the differing loads imposed on theminto account. The inlet camshaft on the leftcylinder bank, which drives the high-pres-sure pump and is therefore subject to se-vere torsional loads, is a spheroidalgraphite casting with electron beam hard-ened cams. The remaining three camshaftsare of the assembled type, for weight rea-sons, with press-fit bearing races and camrings.

Despite the differences in valve posi-tions for each cylinder, the 3 l V6-TDI en-gine’s cylinder heads require only one typeof cam follower, which has been adoptedunchanged from the previous 2.5l V6-TDIengine.

3.6 Coolant CircuitThe coolant flow in the new Audi 3 l V6-TDIengine is now of crossflow pattern, in con-trast to the previous engine’s longitudinalcoolant flow. The engine’s coolant circuit isshown in Figure 9.

The thermostat and water pump are in-tegrated into the engine block at the frontend of the engine. The water pump is dri-ven by a Poly-V belt, and has only one dis-charge-side outlet for both banks of cylin-ders. The ducts connected to it for distribu-tion of the coolant to the two cylinderbanks and the exhaust-side distributionrails are cast into the engine block. Thiscompact arrangement reduces the weightof the engine and also the number of com-ponents needed and the coolant volume.

Because the water jacket is divided lon-gitudinally, most of the coolant flows intothe cylinder heads on the exhaust side ofthe engine block. After flowing across the


5MTZ worldwide 7-8/2004 Volume 65

cylinder heads, the coolant flows back onthe intake side to the inner V of the block,where the flow from both cylinder blocks iscombined and returned either via the radi-ator or directly to the suction side of thewater pump, depending on the tempera-ture of the coolant.

In order to limit the temperature of thewebs between the cylinders at the pointwhere the piston rings reverse their direc-tion of movement, V-shaped bores throughwhich the coolant flows are provided, as onthe 4l V8-TDI engine, through which asmall proportion of the coolant can pass di-rectly from the exhaust to the intake side ofthe engine block.

With the aid of temperature measure-ments and flow calculations, the coolantcircuit was adjusted until the volumetricflow of coolant to all cylinders was identi-cal. Figure 10 summarises the web temper-atures for the cylinders of the 2.5l V6-TDIand the 3 l V6-TDI in the form of scatterbands.

Compared with previous systems, thenew 3 l V6-TDI cooling system significantlyreduces the peak temperatures that can oc-cur. The explanation of this is to be soughtboth in the homogeneous volumetriccoolant flow distribution as a result of theadoption of crossflow cooling and in theuse of the web bores mentioned above.

3.7 Air Supply and Intake Pipeswith Swirl FlapsFrom the charge air intercooler the combus-tion air passes through a throttle flap valve,an intermediate aluminium stub pipe anda charge air pipe and intake modules madeof plastic into the combustion chambers.

The throttle flap is moved by an electricactuating motor with integral positionfeedback. This system permits any numberof intermediate throttle flap positions to bereached and is needed to support the actionof the exhaust gas recirculation (EGR) sys-tem.

The introduction of recirculated exhaustgas at the aluminium intermediate stubpipe has been optimised as far as mixturehomogeneity is concerned by means of CFDcalculations.

For reasons of weight, surface qualityand cost, both the charge air pipe and theair intake modules are made of plastic. Atwin-shell technique with mirror-imagethree-dimensional weld seam is used, thefirst time this has been applied to a high-volume engine; it has the advantages of of-fering increased degrees of freedom and re-duced residual contaminant volume com-pared with friction welding.

The air is distributed to the two banks ofcylinders in the charge air pipe. A series of

CFD calculations enabled the pipe runs tobe optimised to such an extent that there isno more than a 2 percent departure fromuniform distribution.

The air intake modules for each cylinderbank contain an integral flap housing withswirl flap to vary the airflow volumethrough the spiral port, Figure 11. The swirlflaps are injection moulded on to a steelshaft, on to which the bearing mounts havealready been threaded, and inserted intothe housing which at the same time formsthe flange to the cylinder head. Identicallinkages for the left and right banks ofcylinders connect each shaft to an electricactuating motor with position control. Thesame actuating motor is used for bothbanks of cylinders.

The complete system enables swirl andengine air throughput to be adjusted in ac-cordance with a mapped characteristic, sothat the lowest possible emissions and thehighest power output are obtained.

3.8 Exhaust System andTurbochargerAs on the earlier engine, air-gap insulatedsheet metal manifolds are used on bothcylinder banks. Two compensating pipes,also with air gap insulation, conduct the ex-haust to the turbocharger, which is locatedin the V of the engine. A jacket tube madefrom GJV SiMo combines the exhaust gasflows before they reach the turbine of theturbocharger, Figure 12.

The turbocharger has variable turbinegeometry and electric guide vane adjust-ment; it is not supported via the turbine

housing as on the previous engine, butbolted to the engine block by way of thebearing housing and a bracket.

3.9 Exhaust Gas RecirculationSystemAnother important contribution towardscompliance with exhaust emission limits isthe exhaust gas recirculation system (EGR),with switchable flow through the EGR cool-er, Figure 13.

Exhaust gas for recirculation is divertedaway at the point where the flows from thetwo cylinder banks are combined, ahead ofthe turbocharger. It passes through a corru-gated pipe into a water-cooled housing,where a vacuum-actuated flap valve divertsit either through the recirculated exhaustgas cooler or directly to the exhaust gas re-circulation valve. The cooler is flanged to theside of the flap valve housing; it is of platetype, with a high performance rating andlow pressure losses. The gas flows through itin a U pattern. Coolant for the flap housingand the cooler is obtained from the engineblock and returned to the coolant circuit byway of the feed line to the heater.

The pneumatic exhaust gas recircula-tion valve uses an electropneumatic con-verter to control the correct volume of recir-culated gas. A vacuum can of generous size(90 mm diameter) ensures that the exhaustgas recirculation valve opens and closes re-liably even if exhaust back pressure rises,for instance when operating with a particlefilter. The offset valve head improves thevalve’s opening characteristic and thevalve seat, which is machined directly into


3.6 Coolant Circuit

Figure 9: Completeengine coolant circuit


the cast stainless steel housing, has a par-ticularly low contact surface area in orderto prevent the valve from sticking.

3.10 Oil Circuit and CrankcaseBreatherThe oil circuit of the 3 l V6-TDI engine andits crankcase breather are based on the sys-tem used on the 4l V8-TDI engine, but withthe amount of installed space needed, theoil flow, cooling, oil trap rate and road dy-namics requirements all optimised.

The duocentric oil pump is driven at en-gine speed by a slot-in shaft. The internalpump control valve opens at 4 bar and is ac-tuated by the pressure in the main oilgallery. The pump is shutdown in responseto a suction-side signal. A safety valve ratedat 11 bar protects the system against over-pressure when a cold engine is started.

Compared with the oil pump on the pre-vious engine, the discharge volume hasbeen reduced by 40 %, which significantlylowers the amount of power needed to dri-ve the pump. It has proved possible to low-er the total engine oil throughput by sys-tematic reduction of bearing clearancesand a partial changeover from pressurisedto spray lubrication in the basic engine.

The oil filter module, which combinesthe functions of oil cooling, filtration anddirt trap, is located inside the V of the en-gine, where it occupies very little space. Theoil-water heat exchanger, of plate-type con-struction, has been designed for low pres-sure loss and the maintenance of low oiltemperatures when the engine is subjectedto severe loads.

The oil filter can, which is positionedvertically in the oil module, makes oil filterrenewal easier when servicing is necessary;to save weight, it is made from polyamideand is identical with the component usedon the 4l V8-TDI engine. Oil change inter-vals are flexible, depending on the vehicle’sroad use profile, and can be up to 30,000kilometres, though a maximum limit oftwo years is imposed. An oil change on the3 l V6-TDI engine requires 8 litres of oil.

By careful design of the oil return pas-sages and the upper part of the sump, andby reducing oil flow through the entire en-gine, the air trapped in the oil has been re-duced to a very low level.

By making the sump wider and adopt-ing the most suitable dimensions and posi-tion for the oil intake snorkel, the supply ofoil at the correct pressure to the engine isassured even at high rates of lateral andlongitudinal acceleration. Figure 14 showsthe surge angle limits at the minimum per-missible oil level.

The crankcase breather oil trap, Figure15, is divided into coarse and fine oil trap

units. The coarse oil trap consists of alabyrinth in the V of the engine, with theflow reaching it from the front and trans-mission ends. Fine oil particles are trappedby a triple cyclone unit located in the oil fil-ter module. The oil trap has been locatedclose to the turbocharger in order to makeuse of its waste heat and thus prevent theintegral pressure limiting valve from freez-ing even in very cold weather.

The oil trapped in the triple cyclone is re-turned to the crankcase through a leaf-spring valve. This takes up very little spaceand is matched in its setting to the pressuredifferential between the crankcase and thecyclone so that a combination of perma-nent and reservoir drain-back of thetrapped oil is obtained:

At part load, when the blow-by flow vol-ume and the pressure differential are low,the intermittent opening action of the leaf-spring valve permits the oil to flow back in-to the crankcase. When operating close tofull load, however, at high blow-by flowvolumes and pressure differentials, thevalve remains closed. The trapped oil isthen stored in a collector below the cycloneand does not drain back until the engineoperating point is such that the pressuredifferential is lower. The collector volume issufficient to prevent overflowing even atthe maximum possible oil discharge rateand in the most dynamic driving condi-tions, even if the car is driven for thelongest possible distance after refuelling.There is accordingly no risk of the escapingengine oil not being returned reliably to thecrankcase.

3.11 Fuel Injection SystemA third-generation common rail injectionsystem is used, with piezo inline injectorsand an injection pressure of 1,600 bar; thesystem is supplied by the Bosch company,Figure 16.

The CP3.2 high-pressure pump is of thethree-plunger type, and is attached to theengine inside the V at the front. The pumpis driven at 5/6th engine speed by a toothedbelt from the camshaft. The volume of fuelcan be regulated either at a pressure regu-lating valve or by means of an intake-siderestrictor (MPROP). The two forged fuel sup-ply rails are mounted on the cylinder heads.Fuel from the high-pressure pump reachesthe right rail initially, followed by the leftrail. The injectors, which feature the latestpiezo inline operating principle, have a sev-en-hole nozzle and are connected to the railby lines of the same type for every cylinder.

Further information on the injectionsystem is provided in the report on the en-gine’s thermodynamics, which will appearin the next issue.

4 Summary

The new 3 l V6-TDI is the first diesel enginefrom Audi to form part of the company’snew V-engine strategy, with cylinder cen-tres of 90 millimetres and the resultingsynergies and production advantageswhich this brings. It is notable for high per-formance, ample torque, outstandinglygood acoustics and extremely compact con-struction, and also complies with the EU IVexhaust emission limits, even when in-stalled in heavy passenger cars with auto-matic transmission and a Quattro driveline.

The new 3 l V6-TDI possesses all the de-sign features of the latest generation ofdiesel engines: ■ Four valves per cylinder for very lowemissions and, at the same time, maximumpower output ■ Engine block cast from high-strengthGJV 450■ Maintenance-free chain drive to thevalve gear, balancer shaft and oil pump ■ VTG turbocharger with electric guidevane adjustment■ Switchable EGR cooler■ Use of thin-walled castings and plasticcomponents to reduce engine weight

In addition, the V6 TDI 3.0l is notable forthe use of various state-of-the-art technolo-gies such as:■ Third-generation fuel injection systemwith piezo inline injectors and an injectionpressure of 1,600 bar■ Electrically actuated, continuous intakeair swirl adjustment■ Cylinder walls given UV photon surfacetreatment ■ Optimised crossflow coolant circuit

These features make it a milestone inthe volume production of high-perfor-mance passenger-car diesel engines. It is al-so notable for its excellent acoustic proper-ties and low vibration.

With the new V6 TDI 3.0l engine, Audionce again demonstrates its competence inTDI engine design and development.

References

[1] Bauder, R.; Pölzl, H.-W.: Die Geschichte desTDI-Motors bei Audi. In: MTZ-Sonderausgabe"10 Jahre TDI-Motor von Audi", 1999

[2] Bach, M.; Bauder, R.; Endres, H.; Jablonski, J.;Hoffmann, H.; Pölzl, H.-W.: Der neue V8-TDI-Motor von Audi, Teil 2: Konstruktion undMechanik. In: MTZ-Sonderausgabe "10 JahreTDI-Motor von Audi", 1999

[3] Bach, M.; Bauder, R.; Fröhlich, A.; Hatz, W.;Hoffmann, H.; Marckwardt, H.; Pölzl, H.-W.:Audi 4.0 V8-TDI. Der erste Dieselmotor derneuen Audi-V-Motorenbaureihe; Teil 1: Kon-struktion und Mechanik. In: MTZ (64) 2003 Nr.9

[4] Bach, M.; Bauder, R.; Hoffmann, H.; Krebser,R.; Pölzl, H.-W.; Ribes-Navarro, S.: Der V6-TDI-Motor von Audi, Teil 1: Konstruktion undMechanik. In: MTZ (64) 2003 Nr. 5


the new audi 3 l v6-tdi engine

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