Originally Posted by BGTV8

Dude, the explanation is simple - compare apples with apples.

My Z34 6MT has life to date average fuel consumption of 10.7 litres per 100km, having covered 110,000 klms since May-2009

My "other" car, a Ford Falcon utility, running a 5.4-litre quad-cam engine with 6AT has life to date average fuel consumption of 17.8 litres/100km, having covered 120,000 klms since Dec 2007. The "ute" serves on weekend driving around duty as well as tow-beast for race car, so consumption will be increased because of tow-beast duty by (maybe) 10-15% given the amounting of towing I have done.

This is an accurate real-world comparison over two vehicles, both of which have covered over 100,000 klics.