FUEL CONSUMPTION

[prado_1987 Junior Member Find all posts View Profile Close prado_1987]

Re: FUEL CONSUMPTION

bfg a/t meaning tyres i am guessing, thats kinda strange that would have changed anything being different tyres , the tent i can imagine would having drag on the car at high speeds but tyres wow , i am doing a long distance trip at christmas so im going to fill the tank right up and see how many kms i get out of the tank , thats with the car loading with stuff, 2 people and the tent as wel!!!

[ookami Member Find all posts View Profile Close ookami]

Re: FUEL CONSUMPTION

My 2008 D4D Auto GLX, with Toyo bar, was getting close to 1650km per 155 litres.
Since putting on the BFG A/T (std size) I now get a whopping 1350km per 155 litres.

It did not seem to matter, city/highway, fuel usage was about the same, but the BFG's changed everything...

Mine was the same with with once I got Mickey Thompson ATZ and the Roof Rack, I get about 10.8-11.41L\100KM now. I still remember my first tank - 1725kms before the light came on! Now I'm lucky to see 1450kms, but my foot may have gotten heavier now days though :lol:

[gxl_d4d Advanced Member Find all posts View Profile Close gxl_d4d]

Re: FUEL CONSUMPTION

Mine's the same after fitting BFG's. Try cleaning your air flow sensor. My car had become very sluggish over time. The air cleaner was changed at service but no difference. I thought it might have been due to the extra weight of the tyres. I cleaned the sensor and the car drove completely differently. It dosn't hold gear from 3rd to 4th and 4th to 5th and it dosn't kick down 2 gears when going up a slight hill.

I havn't noticed the fuel usage improving. I'll reset the ecu and see what happens.

[mudboy Senior Member Find all posts View Profile Close mudboy]

FUEL CONSUMPTION

I have just added cage and roof top awning and have bfg km2 so I have noticed a slight change but will get better idea over Christmas while away

[mcfisherclan Member Find all posts View Profile Close mcfisherclan]

Re: FUEL CONSUMPTION

where is and how do you clean the air flow sensor?
cheers

[LostDingo2 Find all posts View Profile Close LostDingo2]

Re: FUEL CONSUMPTION

Just filled mine and had the worst tank ever! I knew it was going to be ugly as it has only been in Sydney with some real s$%t traffic. Many days almost an hour just to go about 13-14 k's!

So what I get? Trip (from memory) was like 963ks with 163.3 litres! I have gotten that much from just the first tank! Considering getting some steelies and Hwy treads and placing the STTs on the steelies.

[gxl_d4d Advanced Member Find all posts View Profile Close gxl_d4d]

Re: FUEL CONSUMPTION

where is and how do you clean the air flow sensor?
cheers

It's on top of the air box held in by two screws. I can't post a picture as I don't have a camera to take a picture of it.

Once you've removed it, clean it with contact cleaner, dry it and reinstall it. Before you spray the contact cleaner, place a white tissue underneath so you can see how much crud comes off. The wires should be silver once cleaned and you should be able to see inside the amber bulb at the end.

If the sensor is dirty, the wires down to the bulb will be black and so will the bulb.

[prado_1987 Junior Member Find all posts View Profile Close prado_1987]

Re: FUEL CONSUMPTION

i am currenly doing my christmas trip and have done 1040 kms and im already down to the 90 l tank with half the tank left , thats going by the reading on the gauge , i am guessing im gonna get about 1350 out of 180 l , thats around 13.7 per 100km highway use , mind u i have had my rooftop tent on top ,bullbar and winch , cant work out if this is good?

[ookami Member Find all posts View Profile Close ookami]

Re: FUEL CONSUMPTION

If your running Caltex Diesel Vortex your fuel economy will go backwards - Mine did, got 14l\100km last fuel up, this time round I'm back to around mid 10l\100km go figure!

[Guest Close Guest]

Re: FUEL CONSUMPTION

bfg a/t meaning tyres i am guessing, thats kinda strange that would have changed anything being different tyres , the tent i can imagine would having drag on the car at high speeds but tyres wow

Changing from the standard issue highway terrains to any decent all terrain tyres will increase fuel consumption because of the extra weight of the tyre. Couple that with slightly larger overall diameter and you will need more juice to keep it spinning at the same rotational speed. Imagine trying to swing a light hula hoop around your arm, then swap that with a heavier hula hoop. You will find that your arm gets tired faster with the heavier one. It's known in physics as "moment of inertia".

[gxl_d4d Advanced Member Find all posts View Profile Close gxl_d4d]

Re: FUEL CONSUMPTION

Just filled the tank. I did 630km on 58L. Half on the highway, half in town.

Cleaning the air flow meter seems to have done the trick.

Mine's the same after fitting BFG's. Try cleaning your air flow sensor. My car had become very sluggish over time. The air cleaner was changed at service but no difference. I thought it might have been due to the extra weight of the tyres. I cleaned the sensor and the car drove completely differently. It dosn't hold gear from 3rd to 4th and 4th to 5th and it dosn't kick down 2 gears when going up a slight hill.

I havn't noticed the fuel usage improving. I'll reset the ecu and see what happens.

[Fozzy Senior Member Find all posts View Profile Close Fozzy]

Re: FUEL CONSUMPTION

Where did you get this little gem from Gordon?

I did mine on the weekend and while it's only a seat-of-the-pants impression, it's like I've released some extra horsepower. Car revs more readily, seems smoother. It MIGHT have something to do with going back to the alloys and road tyres after driving on the muddies for three weeks, time will tell, but for a two minute job, results are impressive!

Cheers,

Dave

[ookami Member Find all posts View Profile Close ookami]

Re: FUEL CONSUMPTION

I'm getting quite frustrated by my car, with 3 people aboard and no luggage over a 720km trip at highway speeds sticking to the speed limit with no over taking we averaged 12.2L\100km. I have seen the car do better than this, it almost seems the older the vehicle gets (currently has 21,000km on it and has had is 2 year/40,000km service) the worse the economy gets. Have checked the AFM and ensured it is clean. Does anyone think and ECU reset will help?

[stevensr34 Senior Member Find all posts View Profile Close stevensr34]

Re: FUEL CONSUMPTION

I'm getting quite frustrated by my car, with 3 people aboard and no luggage over a 720km trip at highway speeds sticking to the speed limit with no over taking we averaged 12.2L\100km.

Hmm - doesn't sound great. I've just got 11.0L/100km for my petrol manual 2008 GXL for 350km mostly highway usage, half loaded with 2 adults & 2 kids. And it is raised. However no other accessories, and standard issue tyres: (Grandtreks)

Note that increasing a tyre's diameter does not automatically mean worse fuel consumption: it is just like getting a slightly higher gear ratio, which for highway use probably helps more than hinders better consumption.

The main effect on consumption from after-market tyres is the rolling resistance. This is due to a combination of the tread design, and the sidewall design. If the tyre has more plies then it is more puncture-resistant, but is also harder for the car to "squash" each revolution it makes with the road. The mud terrain tyre tread might make you look tough, but it also create major resistance when rolling on bitumen (or gravel).

If you can hear your tyres "whine" then that is the sound of your fuel being used to vibrate the air around each tread block, when it could be better used to make the car go forward!

[marshallarts Junior Member Find all posts View Profile Close marshallarts]

Re: FUEL CONSUMPTION

I agree, I'd be more than disappointed with 12.2l/100km under the conditions described. I'd be disappointed with anything worse than about 10-10.5. I'm sure the tyres are a factor, but I really think the biggest thing with these diesels is the weight of the right foot. I try to drive for best fuel consumption as much as possible - very small throttle openings, no heavy acceleration, change up early, all that sort of thing. On the highways I tend to cruise at about 90-95. It probably drives a few following motorists up the wall, but that's just bad luck . The ScanGauge is brilliant here - it shows exactly what is happening with fuel consumption under the current conditions on a second-by-second basis. So you very quickly learn what is good and what is not. I've also observed that wind can have a surprisingly big influence - the difference between a stiff headwind and a good tailwind can be as much as 1.5-2 l/100km, even more if you are towing something bulky.

Around town, with just me aboard and not towing, I routinely record about 8.1 - 8.2l/100km - that's slightly less than my 2-litre Forester used to burn! On the highway maybe around 10. It does increase quite a bit when towing the camper, but you have to expect that - it's doing a lot more work. But I repeat, I really believe it's the right foot that is one of the biggest factors, if not THE biggest.

Just my 2c worth.