A blast from the past with my QD32! With the bigger Exhaust, Headers, LPG system, HiFLo Filter and Snorkel, I'm routinely getting about 780km around town from around 68Lt! I do use Morey's Diesel additive for the gas though!
Interestingly though, my economy drops away on the highway with lots of headwind, and/or speed over 110km - approaching 3000 rpm! The figure drops to around 600-650km from 68Lt!
I did a recent trip with a mate running the Series 2 ZD30, and noted that I'm doing higher revs for a given speed, so final drive is different. His economy didn't change much, so my higher revs and my lack of a Turbo take their toll!
Thinking of Turbo very soon! Engine's done 280k, but I take good care of her and a recent compression test came back 440, 440, 420, 400!
Cheers,
Rog