Why is S car fuel mileage so poor?

[Enzeder]

Seems the 8 series number support you, but the 6 series doesn't.  I suppose 
the specs could be wrong.  The forward gear ratios match.

S8 Final drive Ratio: 3.730:1
A8 Final drive Ratio: 2.909:1

S6 Final drive Ratio: 2.727:1
A6 Final drive Ratio: 2.727:1


At 05:26 PM 9/25/2004, S Dewitt wrote:
>Oh and the S cars have a lower gear ratio..
>
>Scott DeWitt
>Advanced Automotion
>817-939-6761
>----- Original Message -----
>From: "S Dewitt" <sdewitt at stx.rr.com>
>
> > You have to make power somehow... More fuel + more air =  more hp..
> > The S cars probably run a richer mixture to combat detonation...
> >
> > Scott DeWitt
> > Advanced Automotion
> > 817-939-6761
> > ----- Original Message -----
> > From: "Enzeder" <enzeder at comcast.net>
> >
> >
> > Why are the S cars mileage numbers so low?  I figured consumption would be
> > a matter of engine load and efficiency.  As both engines are pulling the
> > same weight (and shape in the case of the S8), the load should be roughly
> > similar.  So does that make the S cars 15% engines less efficient?
> >
> > Take the S8 for example.  Two naturally aspirated V8's of the same
> > displacement and hauling the same weight.  Looking at highway numbers (as
> > it's fairly steady state):
> > S8 vs A8 (both 2001)
> > 21 vs 24 mpg
> > 4024 vs 4068 lbs
> > 360 vs 310 HP
> > 317 vs 302 ft/lbs
> > 11.0 vs 10.8 comp ratio
> > 13.9 vs 14.2 ¼ mile
> > 6.3 vs 6.7 0-60 mph
> > An aside: 345x30mm vs 312x25mm (323x30mm for the A8L)
> >
> >
> > As for the S6:
> > S6 vs A6 4.2 (both 2002)
> > 21 vs 25 mpg
> > 4024 vs 4024 lbs (surprised by this)
> > 340 vs 300 HP
> > 310 vs 295 ft/lbs
> > 11.0 vs 11.0 comp ratio
> > 14.5 vs 15.0 ¼ mile (14.7 for the 2.7tt w/6-speed)
> > 6.5 vs 6.7 0-60 mph (6.0 for the 2.7tt w/6-speed)
> > Curiously, both have 321x30mm front rotors.  I expected the S6's to be
> > bigger.
> >
> > Numbers taken from the AudiWorld site.
> >