s4 or a6

[scooters]

ladies and gents.
apologies if this topic seems a little wierd however I'm looking for a larger car due to increasing family. the cars that I have in mind couldn't be more differnet however I'm after some advice on what the running costs would be for each, i.e. mpg, typical servicing as well as reasons for and against.
The cars that I have in mind are as follows:
Audi S4 2.7
Audi Allroad 2.5tdi
Audi Allroad 2.7t
as above but in a6 avant
any other suggestions

by the way, my daily commute is a46 and m4 (stroud to Bristol) so mpg based on A and M roads. Current a3 1.8t is returning around 38mpg on the dial.

any help apprecaited.

Cheers

[NineMeister]

Sorry for the blatant plug, but I'm selling my S4 look 2.5TDi, should you want a car that looks like an S4 but still returns 40mpg:

http://www.pistonheads.com/sales/978565.htm

Just bought an S4 V8 to replace it, and I'm still not sure why I did it .....

[Iainwil]

Had/have both...
Went from the V8 A4, all bit it a cab, to the A6 when we had our first in January.
The way i looked at it was the wife got the A6, so we didn't need the V8 anymore, plus if you look at the room in the boot of the A6 its massive. We've got an 05 plate 2.0Tdi and its great.
Miss the V8 massivly, but one day..maybe an RS6....

[GrahamC230K]

I persoanlly fins the A4 a crampt car so far as rear space is concerned, so if it's for a family car I'd look bigger.

[istoo]

I have had both and A4 avant and a A6 avant. If your you have 1/2 kids and are under five the A4 may fit the bill. More or older, then the A6.
The fair point is the boot as well, the A4 boot is smaller so with a pram/buggy it does occupy in a transverse fashion, but you can put the prams inline in the A6, gives some more space. Despite appearances the A4 is a lot smaller in the back. Dynamically the A6 doesnt drive as a big car, but you will notice it when you park!

Engine wise I have had the 1.8T and the 2.5tdi 180. Both good engines but be careful as they can be sensitive

[phlap]

Due to sprogging I also had the A4 Avant vs A6 Avant conundrum. Not really wanting a barge but needing enough space. The A6 shell as has been pointed out is a fair bit bigger in terms of rear legroom and boot space. With some designs of baby seat in the A4 the seat was jammed against the front seats.

Either would be fine but I chose the A6 which isnt a bus-like as I imagined.

(I know you said running costs are an issue but please check out the seriously tempting prices of loony engined ones before you buy a woodburner!)

[clonmult]

Baby/kid seats in the back of the A6 Avant are almost entertaining - when the woman at mothercare was fitting it, it was one of the few times that she was actually able to stand in front of the seat whilst fitting - most of the time she has to reach over to fit them.

Its a stunningly practical family car - boot swallows up anything I've so far thrown at it (lobbed in my older lads bike yesterday, it just took it no hassle), plenty of cubbies and storage around.

From what I've read the 2.5 diesel isn't even slightly economical, and not really that fast a car either. A tuned 1.9TDi would be a better bet than that for both power, longevity and economy. Other than that all the petrols are (from what I've been told) almost bulletproof. They just keep going ...

[LeoSayer]

Rear legroom in the S4 is woeful, boot space is OK but not great. However, the S4 is certainly the best to drive.

For A road / motorway the A6 and Allroad 2.7T will give you around 20-23 mpg. The 2.5 25-30mpg.

I owned a 2.5 A6 for a short while. The 2.7T is smooth as silk whilst the 2.5 is very far from that. The 2.7T has so much more power and torque across the whole rev range.

[NineMeister]

The 2.5 TDi A4 is not as bad as people make out regarding fuel consumption, mine regularly returns 30mpg on cold start/town driving to work and hit 40mpg when cruising at 70ish mph on the motorway with the cruise control on. The S4 V8 is currently running around 18 around town and 27.5 on the motorway at a simlar sensible speed.