The Simps

Hi, apologies if this has been asked before but other than the obvious improved fuel economy & lower emissions, which is the better engine?

I currently have a 2004 A8 4.2 petrol and a 2004 BMW M3. I'm thinking of selling both in favour of 1 car thats both comfy, stylish, tuneable and fun on the twistys.

Please offer me some guidance as to whether its worth finding the extra ££s to get the newer model.

Thanks.

ChipB

The V6 has better MPG - US figures are city/highway/combined values of 14/22/17 MPG for the V8 and 17/26/20 for the V6. Power is a bit less for the V6 in stock form: 333 versus 354 HP. However, you can pretty easily boost the HP on the V6 with an after-market tune, which can actually exceed the stock V8's power output. The other thing to consider is that the V8 has that marvelous sound - the V8 burble that the V6 can't match.

wieRS5

The better mileage of the V6T is only on paper. When you drive the V6T (S4 or S5) a little bit on performance, it is WORSE on fuel than the N/A V8 (many user stories about this on this and other fora, e.g. my S5 did on average 14,5 liter / 100 km, my current RS5 13,5 liter / 100 km, both more then 20K kms, mixed highway (>100 mph, Germany) and city)

The Simps

So basically, unless I'm plan to tune the engine the 4.2 V8 is the more performance orientated option.

What about the reliability of the engines? Chances are I'll be getting a one with anything from 50-100k on the clock. Doesn't normally concern me with a well maintained car but how big of an issue is the coking up on the V8s? Any other major issues? My A8 4.2 is now starting to pick up little niggles here n there and thats at 110k, which is what concerns me.

mikejaeggi

I second that, my 2014 S5 V6T gulps gas.

The Simps

The V8 so far is looking more favourable!

Can anyone advise on the service schedule? Is it still cambelt at 80k?

Fithian

My 2013 S5 gets 30 mpg on long trips, 21 mpg overall in town. The S5 engine has won best engine award five years in a row (Ward's Ten Best Engines). It is not difficult to chip the S5 to over 400 hp. The V8 is a lot heavier. Better handling with lighter engine up front. If the sound concerns you, the sound can be augmented by the speaker in the engine compartment. Not my choice, but some prefer it. My 9 year old grandson liked it that way.

leetjon00

I'm not sure about that. It all depends on what you mean. V6 stock has much better lower end torque, for example.

IMO, the choice comes down to price, looks, sound, and whether you'd be willing to mod the V6 engine. Either way, I think it'd be hard to make a wrong choice here.

The Simps

Thanks for the info guys. I think its likely to be the V8 model due to price restraints.

I need to consider what mileage I buy the car at now, is there any particular big services due at any particular mileage? I know my current 4.2 V8 in my 2004 A8 has a cam belt service every 80k that is ££££s. Anything on the S5 V8s??

Thanks again.

pdubb

If you want tuneable, go with the V6. I have the V8 and its a dream. Great low end, great handling still (look for an S5 with the Sports Differential, makes a huge difference).

Both will be comfy, stylish and great at handling, but you mentioned tuneable, and if that's the case go with the V6T.

I love my V8, and wouldn't have it any other way currently, but the V6t with minor mods can get over 400hp fairly easily.

As far as maintenance goes, I've only made it to 28k miles, so I'm not too sure.

Both aren't the best on gas mileage, and between the two the difference is like a couple MPG's. Don't let that get in your way. If you're buying an S5, you shouldn't be worried about gas.

Also, the carbon-build up is an issue. I think for 2013 Audi recognized this in their engines and covers this issue under warranty with the S5 2013 and newer MY's (anyone confirm this?)

I will say though, I just got a Carbon Cleaning done on my 2012 S5 V8 covered under warranty, and even though it wasn't sluggish before, you can feel how much more responsive it is now.