FG fuel economy

[PKDreamers]

We just got back from a 5200kms trip Brisbane to Tannum sands across to Bedourie via Diamantina River Road then down to Birdsville and then back over 4 weeks and averaged 17 lts per 100kms. Yes they do drink on the highway when you get the truck going.

 

[westyss]

fuel consumption

I have just finished an 8,225 km trip from Vancouver, british Columbia, to Lake Superior, Ontario, and over all mpg was 16.7 imp, 5.85 km/litre. The faster you go , the more you use is the theme for these un-aerodynamic trucks. Was approximately 10,500 lb's with single rear wheels in an fg140 2007, with alot of stopping. Average speed was 98 km/hour or 61 mph. Fastest speed was 122 km/hour. I would rather still be on the road too instead of back home and at work.
Ill post in the comfort thread too because I used the Aons in the front with some National , air seats and found the ride still very harsh. Some bumps had me slamming my head on the roof. I need a suspension upgrade and shocks, any advice??
Yves

 

[FusoFG]

over all mpg was 16.7 imp, 5.85 km/litre. Yves

is the fuel mileage adjusted for the change in wheel size?

either way, do you think the 19.5" wheels affects your mileage?

 

[1Engine]

When I had my swc installed, the fuel economy before at 80 to 85kph with the 16" wheels did not change when I had the 19.5" wheels installed- I am now travelling at 95 to 100kph.
I have not done a long trip at 80kph since the 19.5's were installed

 

[PKDreamers]

Our FG is bloody thirsty!!!!!!!
Here we are filling up at Birdsville QLD:friday::friday::friday:

 

[Amesz00]

Our FG is bloody thirsty!!!!!!!
Here we are filling up at Birdsville QLD

Hey Pete, what sort of economy are you getting out of it? And what sort of speed you sitting on?

 

[PKDreamers]

Hey Pete, what sort of economy are you getting out of it? And what sort of speed you sitting on?

HI we got av of 17lts per 100kms over 5200km.
Speed is a hard one as you would know out west you can be doing 60kph then slow down to about 10kph, most of the time we sat on about 70-80kph.

 

[Amesz00]

HI we got av of 17lts per 100kms over 5200km.
Speed is a hard one as you would know out west your can be doing 60kph then slow down to about 10kph, most of the time we sat on about 70-80kph.

Thats alright, about the same as what i got up north. yeah i know what your talking about with the speed/terrain...

 

[PKDreamers]

Thats alright, about the same as what i got up north. yeah i know what your talking about with the speed/terrain...

We also stop and start alot looking at stuff and taking pics, wee stops for the boys etc etc.
And it was pretty wet out there with a fair few floodways (if you can call them that) with water over them and the Birdsville track was closed too.
It was a great time to see the desert everything so green and the wildflowers.

 

[Amesz00]

We also stop and start alot looking at stuff and taking pics, wee stops for the boys etc etc.
And it was pretty wet out there with a fair few water floodways (if you can call them that) with water over them and the Birdsville track was closed too.
It was a great time to see the desert everything so green and the wildflowers.

haha, yeah thats what we were hoping for in the pilbara and kimberleys, because they had a late wet, but it was by far not enough, so everything was/is as dry as a nun's undies up north west.

The worst fuel consumption i can remember was in dad's old shorty, coming over the nullabor in a big rush to get home, bout a 20 knot headwind, pushing (thanks to the DPchip) around 120, we were getting around 3.2km/L...

 

[PKDreamers]

We are pretty happy so far with the fuel economy but it does drink a fair bit when you push it along but we like to take our time and see stuff well we try to until you say "oh we got 4 days to get home" then you pull your finger out

 

[doubleb]

do the SWB FGs get any better fuel economy than the normal long wheel base model?

 

[Amesz00]

the 2 feet of difference in length wouldnt make any difference in economy by itself, but it then depends on the style of body (ie how high is it- wind resistance) and the weight of the rig.

 

[Glenn-BJ74]

max engine torque

Engines operate most efficiently (most power per unit fuel use), at maximum torque. The FG engine spec says 347 ft-lbs of torque at 1,600 RPM. So chose tire diameter and diff ratio combination that puts your cruising speed at 1,600 RPM.

What RPM you guys turning??

 

[FusoFG]

Engines operate most efficiently (most power per unit fuel use), at maximum torque. The FG engine spec says 347 ft-lbs of torque at 1,600 RPM. So chose tire diameter and diff ratio combination that puts your cruising speed at 1,600 RPM.

What RPM you guys turning??

I think you are generally correct, especially for engines with a very narrow peak torque rpm range.

But if you look at the graph of torque output for the FG it's practically constant from 1600 - 2400 rpm, and up to 2800 rpm on my older 2004.

So I think drag caused by speed is ultimately going to be the limiting factor for fuel mileage.

I get pretty much the same 15 mpg up to 55 mph (about 2500 rpm) and then it starts dropping off dramatically as the speed goes up or if a headwind is present.

And I don't think cruising speed can be increased too far by lowering the overall gearing through bigger tires because hp is proportional to rpm and low rpm may not generate enough horsepower to over come the drag.