Should I keep? Or should I sawp?!?

[alexevo1111]

Hi Guys,
At the start of last year, my mum was changing her car from an Insignia diesel (grr), so I suggested the A8 D3 (love them).
She went shopping for cars a few days later, and came back with a 2005 (55) A8L 3.0 multitronic (petrol).
Don't get me wrong, I love the car, and so does she, but my god it is s**t on fuel! It is returning around 23-24 mpg av. on the motorway (80mph)...

My mother is not a technical person, but as she does a LOT of motorway miles, she needed a comfy car.
She absolutely loves this car, but I am recommending she swaps it because of the terrible fuel economy.., She doesn't complain about this, but this is because she doesn't understand the relation between mpg and money! I am assuming she just fills up and goes along with the expense...
Although, she is reluctant to change cars, because "she is happy with this one" and is afraid that she will buy a "dud". Kinda the reaction I expected, because she knows little-to-nothing about cars. (I don't know a great deal to be honest, though).
Secondly, this 3.0 has around 127,000 and counting so it's getting kind of risky now (the car is really important for use, and in the last 8 months, she has added 24k)

I am trying to tell her that the 4.0tdi is better on fuel, and that this is what she should swap for.
I know, before anyone jumps in and says it, that it is an old engine, and that it is better to get the 4.2tdi, but financially this isn't possible at the moment, and we are just looking for a straight swap.
And also, we are not interested at all in the 3.0tdi. The extra bit of 'poke' is more desirable in this situation.

Please guys, I just need you to help me explain all of this to her a bit better. I just want to save her a bit of money (money that she doesn't even realise she could be saving).

Thank you very much in advance,
Alex

[M1tchy]

You could work out the weekly milage she is doing and the cost in fuel in the current car. Then the costs if she were to swap and see if that sways her?

Once you start multiplying it by weeks, months and years it will add up and might work?

[alexevo1111]

You could work out the weekly milage she is doing and the cost in fuel in the current car. Then the costs if she were to swap and see if that sways her?

Once you start multiplying it by weeks, months and years it will add up and might work?

Will have to put together a document or spreadsheet of some sort, but will give it a go, thanks
by the way,
what is the fuel consumption like on the 4.0? Is it worth the swap? Also, should she, in your opinion, make the swap for the 4.0tdi?

[zollaf]

if the cost was a problem to her then she would say something along the lines of, oooh, 'this car is crippling me financially'. she is doing the miles so presumably earning the dosh to pay for it. maybe she gets a fuel allowance or something, i don't know and i don't wish to know, but if she is happy with the car then be happy for her. its a big car but even a diesel will still be thirsty and usually more to repair.

[M1tchy]

Will have to put together a document or spreadsheet of some sort, but will give it a go, thanks
by the way,
what is the fuel consumption like on the 4.0? Is it worth the swap? Also, should she, in your opinion, make the swap for the 4.0tdi?

No idea I'm afraid mate, I've got and A7 and never tried an A8. Seems like she is happy with the current car from what you have said?

[alexevo1111]

if the cost was a problem to her then she would say something along the lines of, oooh, 'this car is crippling me financially'. she is doing the miles so presumably earning the dosh to pay for it. maybe she gets a fuel allowance or something, i don't know and i don't wish to know, but if she is happy with the car then be happy for her. its a big car but even a diesel will still be thirsty and usually more to repair.

that's the problem, she won't say if she Is struggling to fuel it, she just goes along with It thinking that 23mpg is what everyone has to account for. She is self employed, also, so she doesn't get allowance. I am happy for her, definitely, but just trying to help her along a bit, either that or just showing her that she can save the money here, and spend it elsewhere.

[EG-4.0TDI]

4.0tdi MPG is anything up to 38 on the motorway (I occasionally broke 40). Note, however, that this drops fast around town or A/B roads. My all up average over about 90k miles was about 33mpg.

I honestly can't advise your mum to swap to one though. The running costs of 4.0 tdis can be absolutely colossal and will dwarf anything she might ever save in fuel.

Search my previous posts for things to look out for on 4.0tdis and you will start to get a feel. Admittedly, many of the issues I have previously posted about are generic to the D3 rather than the 4.0tdi, but specific things relating to D3 cars with the 4.0tdi engine (code ASE) you need to be wary of are:

- Turbo actuator failures. These necessitate whole new turbos (or having them reconditioned). Access is the biggest problem so you're into 10 hours of labour to remove/refit plus the cost of the turbo. If a turbo goes bang, budget £2k. And there are two of them.

- Intake manifold swirl flap failures. These don't tend to wreck the engine (although it is not unheard of) but they do fail emissions and trip warning lights. The part is only available as the actuator and manifold together at £1k. Again there are two - one for each bank and they all fail eventually. Fitting is fairly easy but they need coding.

- Timing chain tensioners. Early 4.0tdis have tensioners that wear too fast necessitating replacement of the entire chain drive. This is an engine out job. 35 hours of labour and over £1k of parts. Budget in excess of £4k, plus all the other bits that you should obviously do in addition whilst the engine is out.

- Rear differential. Early 4.0tdis had a rear differential where there is a known issue with the carrier bearings wearing out prematurely (around 100k). If it's silver in color it's old style, if its black, it's ok. List price on a new rear diff is just shy of £4k. Check my earlier posts for more detail.

- If you're buying above 100k miles beware the gearboxes on the 4.0tdis (ZF6HP26). Because of the design of the quattro system the engine is mounted a long way forward and the sub frame of the car inhibits access to the gearbox. It is therefore impossible to change the gearbox oil filter (which is integral to the gearbox plastic sump) without substantial amounts of car-stripping to gain access (around 12 hours). Therefore no one ever changes the gearbox oil/filter except in dire circumstances. Therefore the clutch packs and friction materials wear and you start to get rough down-changes, slippage, honking between 3rd and 4th on upshifts, and other antics. When you get to this stage the only answer is rebuild the gearbox for £3k or fit a new one for £5k.

On the bright side, they are thumpingly fast and mind blowingly capable cars. The casual and effortless way in which they rip from 50-80 without bothering to change down from 6th puts them a class apart from the 6 cylinder cars which are much less relaxed to drive.

However, at no rational level can I counsel your mum to change to a 4.0tdi as a device for saving money as there is no way she will end up anything other than poorer. That said, she will smile a lot more whilst driving it!

[jugghead]

seen a v8 tdi, can't remember which specific engine size, but i remember the mechanic saying to me that this engine is a nightmare to work on...car was having its turbos changed and it was an engine out job...The car was in bits. front bumper off, loose pipes everywhere...etc etc

[green A8]

EG-4.0TDI.

Interesting info on the 4.0 TDI. I was told ages ago to avoid the early examples and save my pennies to buy a later model. They were regarded as a money pit. One question though, if you don't mind. How do you define an early example? How long was it before Audi fixed the 4.0 engine, and it's seemingly many problems? The only reason I ask is that a relative is looking to buy a 4.0 TDI. As for me I'll stick with my W12, sod the fuel burn! It's the nearest thing to driving a magic carpet, that can suddenly change from a near silent waftmobile into a bellowing monster, great stuff!

[EG-4.0TDI]

Hi green A8,

I think they changed to 4.2 tdi around 2006 so if one were going to get a 4.0 I would reckon on going as late as possible - probably 55 plate if you can find one. Note that it's only the timing chain/tensioner and the swirl flaps that are unique issues to the 4.0 - all the other gearbox/diff/turbo aggro is not guaranteed to be avoided by going for a 4.2!

Good call on the W12 - lovely!

[green A8]

Thanks for that info, I'll pass it along. I think the 4.0 that's being considered is a 55 plate as I seem to remember being told that it was in the lower VED banding. The car is a 40,000 miled one owner beast with FASH. No sign of an autobox service in the service book though. I thought they were supposed to get an oil/filter change at 40K?

[EG-4.0TDI]

Sounds like the right sort of territory. Worth checking the service intervals in the FASH - ie whether there were any huge intervals. Hopefully with only 40k in nine years, it will have been engine oil changed at relatively low mileage intervals which is supposedly much better for the chain drive. The gearbox is 'sealed for life' hence no published service interval for them although that should probably read 'sealed for shorter life'!

[Micha_elD]

You'd also have to factor in the cost of the swap, people will often focus on fuel costs because they are reminded of them each time they fill up, but I've lost about £25,000 on my A8 in the 7 years since I bought it, and spent £11,245 on petrol. If I'd had a diesel, I could have saved 20%, say, £2,250. For the guy that had the car for its first 18months, he had lost £45,000, but he was a director of Barclays, so he probably didn't notice.

Put this another way, every time I spend £100 filling the tank, I should put £220 in an envelope to cover the depreciation.

Overall,fuel costs don't seem to be much of a difference, and given the additional servicing costs of the diesel, I'd definitely pay the little bit extra to have a quiet, silky smooth petrol engine.

For your mum, the HM Revenue and Customs will effectively pay at least a third of her petrol costs for business mileage, so she won't care as much as you