One of the times i did a real fuel consumption check on my 1200 ute was when i drove home from Bendigo in central Victoria one night after the big swap meet.This was the year that i had the 1200GX & five speed in it
I filled the tank before departing & refruelled once only in Holbrook [a little north of Albury] I made it home at midnight after a journey of 450 miles in exactly 450 minutes. I had no problem making that tankfull of fuel last 250 miles [400k] in pure cruise mode at an average speed of 60mph [100kph]

I replicated this mileage figure later in the year when i drove just over 1,700k in a single 23hr period in the same ute. God it felt good to finally get out.