TEG my sister's tiptronic A4 2.8 quattro has all wheel drive and weighs 3505 lbs and gets 27mpg on the highway, so I doubt that the weight is a real issue... Especially considering that bigger GS400 gets nearly the same fuel economy as the IS300... I think the Final drive ratio is the Culprit..Originally posted by TEG:
The auto trans hurts mileage.
The 3270+ lbs hurts mileage.
The agressive rear end gearing (3000RPMs+ typical on the freeway) hurts the mileage.
The soft performance tires might hurt mileage too.
Other than that, it is a mystery...