FUEL CONSUMPTION

[longdog Member Find all posts View Profile Close longdog]

Re: FUEL CONSUMPTION

That's harder to test as it doesn't have a "km travelled" readout.

However, now that you mention it, I think my cycling GPS does have "km travelled" - I'll have to take it for a drive.

What got me thinking about this is that when driving at a stable speed of 110 km/h (according to speedo and GPS), if I press the reset button on the car's trip computer's avg speed display, it will go blank for several seconds then come back with an average speed of 103 km/h. I don't know if it's getting it's info from the same place as the ODO or speedo but that amounts to an error of 6.36%.

So that made me suspect that perhaps it is calibrated to read correctly, despite the deliberate error on the speedo.

[ookami Member Find all posts View Profile Close ookami]

Re: FUEL CONSUMPTION

ENGINE........... 1KD-TE

TRANSMISSION............... 6 speed Manual

TYRE SIZE...................... 265/75/17

ROOF RACKS ETC........... Nill

ANYTHING WHICH MAY AFFECT FUEL FIGURES........ weather shields maybe?

HIGHWAY FUEL CONSUMPTION................ N\A - Haven't taken it away yet

CITY FUEL CONSUMPTION....................... So in its first 1000km of life we've averaged 10.6L\100km, not sure if this is good compared to some but hoping it will improve with more kms. Still is a crap load better than a commodore wagon i was going to buy :mrgreen:

Just as an Update I have now done another 1000kms and have averaged 11.74l\100km - Not real impressed by it now and the fact it can very so much. No change in driving still round town and no towing. Unless the missus is getting under it more or something.

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

Re: FUEL CONSUMPTION

Having fitted 70 profile BFG's, my speedo reads accurately. (Vefified by my handheld GPS).

It appears that Toyota deliberately under-reads the speedo in recent model Prados (when fitted with 65 profile tyres) - this suggestion is supported by many other posts in this forum.

But does the ODO under-read also? Or is the ODO designed to read accurately with 65 profile tyres and it's just the speed read-out that is deliberately under-reading?

With my vehicle fitted with 65 series grandtreks, the odo was out by 5km/h - same as the speedo and verifed by the GPS and a Toyota dealer confirmed that they were set intentionally to read more than actual.

Now that I have fitted the MT ATZ 70 series the speedo is out by 2km/h (reads 100, actual 98km/h) and the odo is also out by the same amount. The only way I have checked this is to select a specific route on the GPS and let it calculate the distance to travel and then set the odo at '0' and check at the end of the trip. The only thing that I have found is that fuel consumption has increased markedly since fitting the 70 series tyres, an increase of around 1litre/100km

[Madkore Avid PP Poster! Find all posts View Profile Close Madkore]

Re: FUEL CONSUMPTION

Just got back from a trip down around the south of WA and recorded my best fuel figures to date.

1312kms travelled, 159ltrs put in, meaning I got 12.12l/100kms! Sweet as! About 1100kms of this was down on the trip, 200kms around town.

I was thinking about what may have changed my figures, and as I did most of the driving on unfamiliar roads, I was mainly going around 100km/h rather than the 110km/h I sit on when driving north of Perth.

Anyway, I am super chuffed with this!

[ntp Addicted PP Member Find all posts View Profile Close ntp]

Re: FUEL CONSUMPTION

Anyway, I am super chuffed with this!

Apparently doubly so! :shock: :lol: :lol:

[Bushbasher Out of control poster! Find all posts View Profile Close Bushbasher]

Re: FUEL CONSUMPTION

Brand new, Perth - Kalgoorlie - Esperance - Kalgoorlie. Auto, D4D.

Managed 9.4litres per 100km. Had to vary the speed on the long run and pushed it to 120 or so a few times (overtaking of course).

I've noticed that it sucks a little more around town and I have been driving very smoothly in order to get the figure up. Will see what happens.

As mentioned elsewhere on this site, I have BFG 70 series and have used both GPS and certified radar unit to confirm speedo is 100% accurate with these tyres as opposed to the stock 65 series which I never used.

But it is way better on the fuel compared to my other 1998 Prado - 90 series 3.4 litre petrol 5 speed manual.

Diesel in Kalgoorlie $129.90 less with your discount docket, ULp at $117.90 so much for everywhere else having diesel close to ULP in price.

[Madkore Avid PP Poster! Find all posts View Profile Close Madkore]

Re: FUEL CONSUMPTION

My apologies - I wish there was the ability to delete your own posts...

[ookami Member Find all posts View Profile Close ookami]

Re: FUEL CONSUMPTION

ENGINE........... 1KD-TE

TRANSMISSION............... 6 speed Manual

TYRE SIZE...................... 265/75/17

ROOF RACKS ETC........... Nill

ANYTHING WHICH MAY AFFECT FUEL FIGURES........ weather shields maybe?

HIGHWAY FUEL CONSUMPTION................ N\A - Haven't taken it away yet

CITY FUEL CONSUMPTION....................... So in its first 1000km of life we've averaged 10.6L\100km, not sure if this is good compared to some but hoping it will improve with more kms. Still is a crap load better than a commodore wagon i was going to buy :mrgreen:

Just as an Update I have now done another 1000kms and have averaged 11.74l\100km - Not real impressed by it now and the fact it can very so much. No change in driving still round town and no towing. Unless the missus is getting under it more or something.

Ok another update, last tank i got 11.3l\100km, its getting better again but still not exactly 9.2l\100km quoted. Any idea when the engine should loosen up if at all? Do the D4D chew much more fuel if driven "spiriedly"?

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

Re: FUEL CONSUMPTION

ENGINE D4D

TRANSMISSION Auto

TYRE SIZE. Standard 265/65/17
ROOF RACKS ETC no

ANYTHING WHICH MAY AFFECT FUEL FIGURES 1300 -1400 kgs of Jayco Poptop

HIGHWAY FUEL CONSUMPTION 12.5 to 13l/100 kms when towing

CITY FUEL CONSUMPTION don't take the van or Prado there if I can help.

Very happy with the fuel consumption and the range between fills.
It will be very interesting to see what consumption is like when I connect the new 2000 kg plus van

[Prado BB Advanced Member Find all posts View Profile Close Prado BB]

Re: FUEL CONSUMPTION

Just did a recent trip to Melbourne and back with my brother following in his v6 120 prado. The results:

ENGINE........... 1 KZTE - 3lt TD

TRANSMISSION............... Auto

TYRE SIZE...................... Standard

ROOF RACKS ETC........... Alloy Bullbar

ANYTHING WHICH MAY AFFECT FUEL FIGURES........5 people + luggage

AVERAGE FUEL CONSUMPTION................Mine = 12.3lt/100 , my brothers = 16.5lt/100 ops:

The odd thing on both cars was that when the "90lt" second tank light came on, we estimated that we had used 107 litres, which meant we only got about 63 litres "usuable' out of the second tank. So for the first tank (when the light came on - I had travelled 880km, the v6 650km.

Having read through the various threads, I see that some are claiming around 100 litres used before the light comes on. I will search the site for more on this!!

cheers
Andy

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

Re: FUEL CONSUMPTION

1237km, 124.3L. 300mL Chemtech Diesel Power added to clean injectors. 80% highway, 10% town, 10% hard dirt track.

GXL, Automatic, soverign bull bar, 2 bar roof rack, 3 people and luggage.

[Bushbasher Out of control poster! Find all posts View Profile Close Bushbasher]

Re: FUEL CONSUMPTION

Has anybody done a long enough trip over constant terrain whereby they have seen whether they actually get the same out of both tanks?
Mine seems to get a lot more from the first tank than from the second. I know it's probably using all the fuel in the filler pipe as I always fill to capacity.
Maybe I'll have to take a run to Eucla and back (1800km) and see what happens.

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

Re: FUEL CONSUMPTION

Bushbasher,
I think you will find that the change over occurs closer to 100l than the 90 the message on fuel guage gives.

On page 5 of this thread Fawcett said

Hi Guys, new to the forum. Purchased a 2008 GXL D4D Manual in August and have done 5000km now. Driving home from Brisbane to Darwin we averaged 10.7l/100km on the first couple of tanks.
I started to get curious when i got worse mileage out of the second half of the tank too, so i waited until the 90L light just came on and filled up only to find out that it took 100L to fill. Its one of those things where i guess you dont read your gauge too accurately and just go by how many km per tank you have been averaging.

My scanguage indicates closer to 100 too.

[Bushbasher Out of control poster! Find all posts View Profile Close Bushbasher]

Re: FUEL CONSUMPTION

This bloody scanguage thingy. I filled up and scanguage predicted 73 litres but the car took 107. I then went into the menu and made the correction which was something like 43% increase. Hopefully now the scanguage will show the true figures. The thing is that the green "90 litre" had only just illuminated when I did the re-fuel. Going up the highway tomorrow to see how it goes.

With all the piping required to manage two tanks I'm guessing there could be a rather large amount of variation when you fill up when you have one tank empty and the other only partially full.

[MickL Addicted PP Member Find all posts View Profile Close MickL]

Re: FUEL CONSUMPTION

Mine seems to get a lot more from the first tank than from the second

The reason for this is in the way the fuel system works. You don't have two seperate tanks that are switched between (like the 90 series).

The second tank should be thought of as an "extension"to the main tank

The system works by taking fuel from the main tank and pumping it to the injection pump or fuel rail (depending on engine type)

The return line from the engine goes through a "Jet pump" which is in the main tank but sucks fuel from second tank. (more fuel is pumped than used by the engine for lubrication and cooling the injection system etc)

The jet pump pumps fuel to the main tank and tops it up whenever fuel is flowing (Engine running)

A jet pump uses no moving parts. Think of it as a funnel with a high pressue jet firing into the middle of it. The pressure stream draws in surrounding fuel into a lower pressure, higher volume stream.

So.... to pump fuel out of the second tank you are in fact using an amount of fuel from the main one to make the jet pump work.

Here's a diagram of a jet pump which will hopefully help explain how it works:



Mick