Out of the box thinking : fuel economy improvements ; fg649

seagulljim

New member
Gday all

2004 fg649 3.9 l turbo deisel
Electronic controlled injector pump
Tyres 19.5 bridgestone m840 265x70
Standard exhaust.
We cruise at 90kmh max and are "mechanically sympathetic"
Any solid out of the box thinking in regards to tyres and servicing hints or tricks to improve fuel economy in this veichle please.
Thanks
 
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Aussie Iron

Explorer
My biggest fuel economy increase was when I regeared my transfer case. Made close to 2 Litres/100K's improvement highway cycle. Improved offroad ability also with lower Low Range gearing.

Dan.
 

glennm01

Member
I converted 2 liters/100 km into 'Murican, and came up with a 117 mpg improvement. Impressive. Either I'm doing something boneheaded (not unlikely), or there's a missing decimal somewhere.
 

yabanja

Explorer
We get 13 mpg on 37" tires. Honestly for the weight/size of the vehicle (10000 lbs) I consider that to be very good. I don't know of another vehicle of this type that gets better.

We did increase to a 50 gallon tank which nets us 600 mile range.
 

Lovetheworld

Active member
I converted 2 liters/100 km into 'Murican, and came up with a 117 mpg improvement. Impressive. Either I'm doing something boneheaded (not unlikely), or there's a missing decimal somewhere.
He probably means that he came from something like 18 liters on 100km to 16 liter on a 100km. So 2 is the difference, which you put in as if the vehicle did 2 liters per 100km leads to that result.

Difference between amount of distance per volume of fuel, and volume of fuel needed per amount of distance.
 

glennm01

Member
He probably means that he came from something like 18 liters on 100km to 16 liter on a 100km. So 2 is the difference, which you put in as if the vehicle did 2 liters per 100km leads to that result.

Difference between amount of distance per volume of fuel, and volume of fuel needed per amount of distance.
Yes, yes, yes. Of course. Thank you. I am indeed a bonehead.
 

Aussie Iron

Explorer
It's all good, I thought you would work it out or someone would enlighten you. And yes I came from just under 18l/100 (17.95) to 15.9.

Dan.
 

seagulljim

New member
My biggest fuel economy increase was when I regeared my transfer case. Made close to 2 Litres/100K's improvement highway cycle. Improved offroad ability also with lower Low Range gearing.

Dan.
Dan
Very significant improvement and you simply won't get better than that.

I have followed past threads about your conversion and is certainly viable over the long term for money spent however the initial cost upfront for me at the moment is prohibitive.

Are there any sensors that require periodic servicing that would lead to slight gains perhaps due to the computer controlled I. P. ?

I run the skinner type tyres (less friction on the road)

Taller 19.5 tyre is claimed to improve economy at cruising speed (refer old threads from A.T.W. referring to n.s.w. fire brigade trucks,
I have no way of knowing this as the veichle was fitted with these wheels upon purchace)

Just trying to split the atom and gain any improvement however slight.

Thank you for your advice
 

Peter_n_Margaret

Adventurer
Off topic, but if the rims are 8 1/4" you should seriously consider changing to 305/70R19.5s. The ride will improve "out of sight".
I am a Michelin fan and use XDE2+. I consider they have a lower rolling resistance than others.
Cheers,
Peter
OKA196 motorhome
 

blackduck

Explorer
Gday all

2004 fg649 3.9 l turbo deisel
Electronic controlled injector pump
Tyres 19.5 bridgestone m840 265x70
Standard exhaust.
We cruise at 90kmh max and are "mechanically sympathetic"
Any solid out of the box thinking in regards to tyres and servicing hints or tricks to improve fuel economy in this veichle please.
Thanks
just curious what your weight is, what economy your getting and what you would like to be getting. My 07FG gets between 17 and 20L/100K at 90Kph fully loaded with 30' van in tow. thats pretty reasonable i wouldve thought.
mind you as soon as i creep past 90 then things change
 

seagulljim

New member
just curious what your weight is, what economy your getting and what you would like to be getting. My 07FG gets between 17 and 20L/100K at 90Kph fully loaded with 30' van in tow. thats pretty reasonable i wouldve thought.
mind you as soon as i creep past 90 then things change
6 ton loaded truck pulling 3.5t offroad van.
Unloaded and not towing around 18l per 100klm
Loaded and towing around 22 to 25l per 100km depending
Cruising speed 90k
I know this is the average for this veichle but however open to any out of the box thinking for any gains however slight.

Modifying exhaust from turbo back next year 3.5 in dump (as advised by local exhaust guy) to 3 inch exhaust brake and thru twin hot dogs as recommended by local veichle inspector as I require only 99db being a n? series veichle
This I hope will assist with some fuel economy improvement.

The figures you've quoted from my own experience I belive are brilliant and same as what you'd expect from a landcruiser

Open to any other thoughts and advice

Thanks
 

westyss

Explorer
I have met a guy who has set up propane injection for his truck and it looked to be a simple setup, its been a while since I saw it but it was led into his air intake somewhere and he uses a remote valve to switch it on and off, I have been keeping my eye open for him so I can check it out again and get some pictures.
Also when I was in Leavenworth Washington I met a fellow who installed a spicer gear splitter? I think he called it, doubled his available gears and he stated his available power increased.
 
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