VW Touareg TDI, Audi Q7 3.0L TDI engine

The VW Touareg TDI and Audi Q7 TDI use the same 3.0L TDI engine, model name "CATA".  It's a V6, common rail injection single turbo diesel engine.  Here are some FAQ and technical details on the V6 TDI engine.

If there is a 2011 or 2012 Audi A4 TDI confirmed for the US or Canada, this diesel engine is the obvious choice since it's already set up for the body and Audi quattro (VW 4motion).  No other engine offers this combination of power and excellent fuel economy for mid size-large vehicles.  In the VW Touareg or Audi Q7 TDI SUV it gives more torque than the Touareg's gas V8 (at a much lower engine RPM) with the economy of a V6 midsize sedan.

Since it's a modern common rail diesel, it's quiet running, easy to start, and smoke free.  The emissions treatment system makes it emissions legal in all 50 states.  The Touareg or Audi Q7 qualified for a $1150 federal income tax credit which is now expired. Power in the Touareg and Q7 are rated at 225 hp and 406 lb-ft of torque at only 1,750 rpm.  EPA rating in the Touareg is 17 city/25 highway, significantly more than the V6 or V8 gas engine Touareg.

Some of the technology on the CATA 3.0L TDI engine is common rail fuel injection which uses extremely rapid piezoelectric (like the vibrating sonicare toothbrush head) injections of fuel at about 29,000 psi!  To compare, the average gasoline engine injects fuel at about 60 psi.  The turbo is a VNT variable nozzle turbo.  The big difference is that it appears the VNT actuator on the CATA engine is driven by an electric motor instead of a spring/vacuum.  The new common rail TDI also use 4 valves/cylinder.

Some differences with the smaller TDI engines are an emphasis on performance.  The 3.0L V6 engine has 50% more displacement than the 2.0L engines in the smaller VW and Audi TDI.  For larger or heavier cars, it could be the perfect engine because it combines performance and fuel economy.  The CATA engine weighs about 490 lbs and compression is 17:1.  The V angle is 90^o  and the crank pins are 30^o  offset for even firing.  It also uses twin intercooling to cool the larger air requirements vs. the single intercooler on smaller engines.  The smaller engines do get much better fuel economy but they're also mounted in much smaller and lighter cars.  Each cylinder head has its own common rail.

The 8 speed transmission equipped with this engine for 2011 and later models is designed to handle up to 627 lb-ft of torque so it should be responsive to power upgrades like a chip or tune.

Source : myturbodiesel

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