A8 D3 Sport - 3.0 or 4.2 TDI?

[M5Sime]

Hi all,

Does anyone have opinions on the merits/pro's/con's of the two diesel engines..

Clearly the mpg is similar, the V8 is more powerful and is heavier in the nose...

What in the real-world is the best engine for the A8? Does the V6 3.0 feel a little underdone?

Model year would be circa 2006/7 likely.. I think they tweaked the 3.0 V6 and I know the 4.0 TDI moved to the 4.2..

Any other general advice on these superb cars (Warranties, running costs etc)

Cheers

Sime

[Dr G]

Personally I would go for a 3.0 - performance is very good indeed standard. With a map on these they go like stink and economy is even better.

Just test driven a customer in a 56 3.0 TDI; chap has currently an Omega MV6 and was certain the A8 would walk all over it in performance terms.

I've not yet driven a 4.2 V8, only the old 4.0 which I am informed is a boat anchor in comparison.

[Dilligaf10]

3.0TDi with a bit of "fettling" is the way to go.

Mine gets excellent mpg, usually around 45 on a run with an average of 40mpg over the last several 1000 miles. Excellent performance and beautiful relaxed cruising. Surprisingly nimble handling for such a big car as well.

4.2 V8 has a lot more power and torque but think that the handling suffers because of the heavier engine.

Avoid the 4.0 TDi like the plague, old technology and a rough sounding engine in comparison. V6 3.0TDi is silky smooth.

[M5Sime]

Thanks guys!

Both of you are advocating the remapped V6 then, over the V8. So the standard product is not that sufficient?

The V8 official MPG is not that far off that of the V6 (and has so much more power). Thanks for the tip on the 4.0 v8. I was not planning to go for this one

Cheers

Sime

[Dr G]

Standard product is very good indeed... but too much power is just enough

[Dilligaf10]

Dr G said:

Standard product is very good indeed... but too much power is just enough

a Meatloaf moment!! (You took the words right out my mouth)

[ukdennis]

M5Sime said:

Thanks guys!

Both of you are advocating the remapped V6 then, over the V8. So the standard product is not that sufficient?

Just pootling around town, you'd think that the standard 3.0tdi was all you'd ever need. However, on a fast A road overtake, you'd soon learn that the torque falls off rather dramatically after 3200rpm and that kills the fun somewhat. Even the 6 speed auto can't disguise it. With the remap that I've had done (same firm as Dilligaf), the hp is increased to 273+ and the torque to 500nm+, both of which are noticable, but even more evident is that the torque plateau now persists past 4000rpm which makes a hell of a difference. The reason there is a "+" after the hp and torque figures is that with an auto transmission on the dyno, they can never use full throttle without getting kickdown and that would give a false reading.

[M5Sime]

Hi UKDennis,

Thanks for the comments! Have you tried the 4.2 V8?

Have you heard the Bose vs the B&O? I managed to find a youtube clip of the 5th gear test (crap) where they tested the two (well sort of).

Any other pearls of wisdom you can share?

Cheers

Sime

[ukdennis]

No I haven't tried the 4.2 V8, either as a petrol or diesel. I imagine that the petrol would be lacking in torque (only by comparison to the diesels) until it hits midrange. The V8 diesel would no doubt be quite something with 650nm of shove, but as Dilligaf says, the engine is substantially heavier and would no doubt impact handling. Perfectly good though, for cruising and surprising sports cars at the traffic lights!
I have the Bose system in my A8, and sounds fantastic. Not tried the B&O.

[Escort2dr]

Dilligaf10 said:

3.0TDi with a bit of "fettling" is the way to go.

Mine gets excellent mpg, usually around 45 on a run with an average of 40mpg over the last several 1000 miles. Excellent performance and beautiful relaxed cruising. Surprisingly nimble handling for such a big car as well.

4.2 V8 has a lot more power and torque but think that the handling suffers because of the heavier engine.

Avoid the 4.0 TDi like the plague, old technology and a rough sounding engine in comparison. V6 3.0TDi is silky smooth.

Blimey, that's pretty good economy. If I'd known that, I might not have gone for a 2.0tdi A6

Although I've had 3 A4s and now the A6, I'm not familiar with the A8 so much - are they all autos?

[ukdennis]

Escort2dr said:

Although I've had 3 A4s and now the A6, I'm not familiar with the A8 so much - are they all autos?

The A8 quattro's are all torque converter autos but with tipronic to give a semi-manual mode (flappy paddles). The poverty spec A8 with the small petrol engines can be had with multitronic, though if you've read about those on a different thread on this Forum you'd avoid. No manual option on any of them, but I don't think a manual would suit the ambience of an A8.

[M5Sime]

Hi Chaps,

What about the topic of warranties and general care and attention with these beasts!

Any must have options?

Cheers

Sime

[Dilligaf10]

They come with a pretty high spec to start with anyway but mine has a few options that I find I would now miss including adaptive headlamps and surprisingly the TV option. (I spend a lot of my time waiting at airports!).

I extended the standard Audi warranty when it expired with one from my main stealer which mirrored the Audi one but was cheaper. The only things that have been needed are a new folding screen mechanism and a replacement radiator that I did not even know was leaking! There may be an issue with a batch of faulty injectors for the 2006 model year but I am still investigating this.

The keyless entry system is excellent although when I drive Mrs D's Mercedes I make myself look stupid trying to open the door without "plipping" the car first.

Not all A8's have flappy paddles, only the Sport spec IIRC.

All in all, supreme motorway vehicle that is nimble on the twisty bits. Good economy and performance, understated absolute luxury.

[M5Sime]

Dilligaf10 said:

All in all, supreme motorway vehicle that is nimble on the twisty bits. Good economy and performance, understated absolute luxury.

Thanks for the info and description! I even see that some of them have Sky Digital TV with a small receiver on the boot lid I guess (or was this just the D2s)...

I am definitely not being put off by any of the comments fo far! :-))

Cheers

Sime

[ukdennis]

Mine is an SE, not Sports and it has flappy paddles. So I don't know if this is non-standard or not.

Regarding the TV, yes it is a very nice thing to have! The standard TV module in mine is broadcast only (2005/05). I would need to upgrade it to receive Freeview (if I was still in the UK that is!) before the digital switch-over whenever, no doubt at great cost from Audi. Others can probably fill in the gaps.

[Escort2dr]

There are loads of retrofit companies who could probably upgrade it to digital at lower cost than Audi.

[Dr G]

Gareth @ Hazzydays is the man for this, very knowledgeable and professional (www.vwcruise.com)

The post remap power curve is night and day:



Torque stays for longer and power band is stronger and longer (positively Andrex like).

[AKA8]

ukdennis said:

No I haven't tried the 4.2 V8, either as a petrol or diesel. I imagine that the petrol would be lacking in torque (only by comparison to the diesels) until it hits midrange. The V8 diesel would no doubt be quite something with 650nm of shove, but as Dilligaf says, the engine is substantially heavier and would no doubt impact handling. Perfectly good though, for cruising and surprising sports cars at the traffic lights!
I have the Bose system in my A8, and sounds fantastic. Not tried the B&O.

The torque figure for the petrol sounds quite low at 315lbs/ft approx, but it seems to work quite well due to the weight of the car. But, the smaller petrol engines just don't do the job as well as the 3.0tdi. I figured mine using an iphone app, Dyno +, and it calculated 0-60mph at 5.9 secs, in line with Audi's figures. Interestingly, 30-70mph figures for the petrol and diesel V8's are virtually identical. However, a remapped 4.2tdi is meant to be S8 quick in many respects.

I still get 28mpg out of mine on the motorway consistently doing 85 leptons per hour.

[M5Sime]

AKA8 said:

I still get 28mpg out of mine on the motorway consistently doing 85 leptons per hour.

Hi.... And you have the 4.2 V8 Petrol? or the TDi and get 28mpg..

I plan to drive it briskly for 110 miles of motorway and some A roads each weekday... Are the official figures of 30 and 33 mpg for the V8 and V6 diesels respectively achievable?

Thanks

Sime

[Dilligaf10]

Averaging 40mpg over the last 15k miles mixed motorway and town driving, with 44+mpg on motorway runs.

Mrs D has got the record at 49.2mpg to Gatwick and back from Gloucestershire!