Fuel Economy

[brindo]

My one tonner has always had woeful fuel economy. Even as a stock standard V6, it drank fuel, and me adding another 2 cylinders did nothing to help this. Regardless of whether I drive it or my wife drives it, it generally gets the same 18 – 20 mpg on the highway in its current state.

So recently did another trip to collect some turf for the yard - around 900 kms all up there and back. The trip down should have been ideal for fuel mileage. Left early in the morning so it was cold – maybe around 4 degs - so no air cond, and fog for most of the way so average speed would have been slower. But still got just under 20 mpg the same as it would any time of the year.
Collected the turf, and I unload the pallet a bit mainly to stop the sheets that stick up higher than the cab getting wind burnt. Fully loaded it’s obviously a lot more sluggish, but it still manages to get along OK. But fuel economy actually increased to a bit over 24 mpg coming home.
Apart from the handicap of the extra weight, I had the air cond on for most of the way home as it was hotter, and I managed to stay on the posted speed limits. I didn’t do any logs, but it would have to be in a different section of the of the fuel and ignition maps. But I am thinking maybe aerodynamics may have had something to do with the increase??? Maybe less drag from the load in the tray??? Sitting a bit lower wouldn't hurt either. Not sure anyone would buy a tray back ute for their aerodynamic efficiency though, but a 4 mpg increase is fairly sizable.

Interestingly, I went over the weighbridge before I got home and was on the wrong side of the GVM at 2.92 tonne.

[Dylan]

For what it's worth I have a VZ V8 Crewman. I don't think much of the economy. 18L/100km around town 14 on the highway.

[HQ355]

Have you had it tuned ? My old VX ls1 use to do 14l/100 around town ( giving it a flogging most times) and well under 10 on the highway. Even when I had my caravan on the back it would do 13l/100

[Dylan]

Mines untuned all stock but has about 270xxxk's which wont help. Always run 95 octane fuel. And it's absolutely gutless too.

[brindo]

Haven’t really done a great deal with the tune, but it goes OK. The motor (and trans) have over 230K on it now but it doesn’t use any measurable oil yet.
But I was getting just on 30 mpg out of 304 in my old VS ute, which had the same injectors, same lean cruise values and similar ignition timing.

[psyolent]

My VX Berlina V6 returned 8.1 / 100KM on my trip down from Tumbarumba on the weekend. Was bloody awesome!