2.7 TDI vs 3.0 TDI and what to look for


Registered User
Hey guys,

First of all, I apologize if this topic has been covered previously.

I currently own an A3 8P and looking to upgrade to the A6. I am aiming at 2004-2006 models with 2.7 or 3.0 TDI engines. So here go my questions if anyone could answer them, I would be very grateful:

* Which engine to go for, which one is more reliable? Is the power difference big (in subjective terms)?
* Are the MPG figures very different between these engines?
* Which transmission to go for (for each engine)?
* What are some of the most common faults of both engines, what should I look for when buying any of these?

Thanks in advance!


Well-Known Member
VCDS Map User
All V6 TDI engines around that age had injector issues, a simple test is to leave the engine to idle for a while (must be hot) and if it starts smoking then the injectors need replacing, also lots of smoke under hard acceleration is a good sign of failing injectors. The cost for 6x injectors will be around £1,600 new. Two of the injectors failed on my 2006 3.0TDI so got a used set from a 2010 V6 engine for £500 and it been fine ever since so it can be done on the cheap.

You should get better MPG on the 2.7 (fwd) unit, but with a V6 engine are you really bothered about MPG as it's never going to be great and it's a heavy car. Remember the 3.0 is quattro only so your dragging a good few kg of extra metal work, quattro models also have a bigger fuel tank (extra 10 liters).

The 3.0 has a better Auto box, not sure about the manual.

I've driven the 3.0 manual & Auto and personally I think that size of TDI engine it suits the auto box. Also when I'm in the A6 I just want to be lazy!

On a cold start check for a chain rattle, you may hear it for a second or so but any longer then it could be ££££ to get that sorted.


Registered User
Thanks a lot @B5NUT !

As for the MPG, just asking for informative purposes, I know it isn't going to be anywhere near my current 2.0 TDI A3 with either of the 2 engines. :)