Torque test

FUEL consumption is mainly determined by how you drive and 17.5 litres for 100km out of your 5.7-litre LS1 V8 ute suggests you have a heavy right foot. The 14.0 litres per 100km you quote sounds like the official ADR fuel consumption figure and not real life, so it's not comparable with your own experience. I reckon you would get slightly higher fuel consumption out of the 6.0-litre LS2 V8. Higher torque can help fuel consumption by making it easier to drive the ute with less throttle opening. The 6.0-litre LS2 went into the ute in February 2006.