I got back from my trip did 835K round trip i had tank filled to the brim when i left, was a lot of traffic all the way to Katoomba ( as normal ) i just drove on speed limit useing my GPS was 110KPH and was over the Great Dividing Range so some twisty bits and some big climbs and desents. Rained all the way. and on way up was cold with outside temp reading 4C at one part thats the coldest it has ever read, in Sydney cold to me is 15C. well as i said i did not take it easy just drove normal and no one overtook me, had two VW 2.0 TDI and a Mazda 3 all had fancy mag wheels, but that poverty pack i30 did the job in the wet even down mount Victoria Pass , no problem with the Kumho Tyres they held on ok.
anyway i filled up at same servo same pump on my return and took 41.48L to fill to brim like when i left so i think 4.96 L / 100K. will do pipe this weekend and in three weeks do same trip same style of driving. see what i get.