D40 Fuel Economy

My 08 2.5 Man gets about 10.4lt/100km around town. No highway km's yet. Has 35000 on the clock.

Just returned from an almost 19000km trip around Aus. From Queanbeyan NSW to Albany WA via the Nullabor, up to Steep Point (substantial deep sand and heavy corrugations), up to Exmouth and then out to Karajini NP, back to the coast before heading to Marble Bar and then...Carawine Gorge, Telfer Mine Rd, Wapet Rd, Gary Highway, Gunbarrel Highway, Heather Highway, Great Central Road and into Alice Springs. Next off to Mt Dare and across the Simpson Desert via the French and WAA Lines - over Big Red and on into Birdsville. Then down to Innamincka and the corners before heading east to Cape Byron and then up to Hervey Bay and back home to Queanbeyan. My 08 auto D40 was loaded to the hilt with lots of shite on the roof as well......bit like trying to move a block of flats really. The fuel consumption for this trip was 14.2 ltrs/100km (did I mention how much sand, corrugatiions and generally all round crap roads there were!). The vehicle now has 32000km on the clock and is 9 months old. I'm pretty happy with the consumption as it stands at the moment.

D40 bush pinstriping said:

G'day Guys,
I've been researching for a while what the best options are for D40 T/D Auto fuel milage are and wondering if someone can help with the myths to help improve. I am a qualified Diesel Mechanic with Electronic diesel engine management exp as well but been away from the industry now for a bit,
I don't really care how much the fuel costs, got a fuel card, but want the range!!
I'm Looking at removal of DPF and "Cheating" the sensors with normal exhaust pipe?
Looking at blocking the EGR valve, heard this can work, not sure if this was done on a auto or manual to improve economy?
Upgrade exhaust?
I'm currently getting the run of the mill 450-490km before the light comes on, my mate has a 06 RX d40 T/D Auto, and he's getting 420-450 for half a tank, only difference is he's running 31's and i'm on 32's.
We both have the same extra's as in, bullbar winch, canopy ect, ect, but his with 50,000kms will acheive factory specs (I occasionly use a DP chip and get slightly better economy, but alot of soot)
(I'm also using the correct oil specified for DPF.
Love to know if anyone has recovered their T/D auto from the poor figures back to something reasonable?

Thanks,

Tim

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hey Tim..

may or may not be any help... but i have removed the DPF from my 08 Auto STX and it has made no difference in anyway.. apart from a lil noise..

Having troubles with the sensors atm.. they are all plumbed into a pipe that was made up.. so every 3 wks i get an engine light come up..
Also.. im pretty impressed with the 490km your getting and your mate to get 420 with half a tank... ill get about 400 til the light comes on..
Ive just put a set of 33's on today.. se will see how that goes now..

petrol V6 average 14-16ltrs /100 km VQ 40 series motors worlds top 10 built motors love it plenty of power was going to buy a diesel but couldn't trust Nissan Diesels after having a Patrol ZD 30 3ltr engine 93,000km shit it's self serviced every 5000km still went. No more Nissan Diesel's for me didn't like the 2.5 ltr 4cylinder motor time will tell in thier longativity.

Hey guys, I to have to Navara d40 auto and getting around the 14L/100km have done about 16000km I have spoken to the guy i got the vehicle from and he said that the computer in these Navara’s will need a reset especially if the battery has gone flat. Or the fuel system has the ability to learn and can sometimes get confused and use excess fuel. He said to bring it in and they will reset the computer under warranty and all should be fixed. will let you guys know how I go.

my 08 2.5 d40 with 265 75 16 under it got 601km for 69ltr. on the highway 110km-120km. they say there is a 6% reduction in the milage cause of the larger tyres.
only got 25 000km on it and hope it gets better as time goes on as they claim to only use 9ltr per 100km.
i have my doubts.

westy350 said:

Hey guys, I to have to Navara d40 auto and getting around the 14L/100km have done about 16000km I have spoken to the guy i got the vehicle from and he said that the computer in these Navara’s will need a reset especially if the battery has gone flat. Or the fuel system has the ability to learn and can sometimes get confused and use excess fuel. He said to bring it in and they will reset the computer under warranty and all should be fixed. will let you guys know how I go.

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Mine gets around same figs as yours, a bit worse since I put 265/75 MTZ's on, went back to Nissan and they said computer was fine & its cos i'm carrying too much weight.
Seems like the auto's are a bit thirsty.
Someone on this site said to clean the airflow sensor & reset the computer to fix up. Can't remember which post though

D40Junky said:

hey Tim..

may or may not be any help... but i have removed the DPF from my 08 Auto STX and it has made no difference in anyway.. apart from a lil noise..

Having troubles with the sensors atm.. they are all plumbed into a pipe that was made up.. so every 3 wks i get an engine light come up..
Also.. im pretty impressed with the 490km your getting and your mate to get 420 with half a tank... ill get about 400 til the light comes on..
Ive just put a set of 33's on today.. se will see how that goes now..

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Cheers mate,
I wasn't all that positive on removing it but science tells you any restriction to flow is bad ju-ju. I'm running 265/70-17's 4 RIB ATZ's which shouldn't kill it too bad, but I can see why it can kill the economy. I also like the thread put in about the computer being reset as I had the factory battery shit itself by polling itself out at around 1500kms.
will keep on keeping on with the info, thanks for the mate,

Tim

Well it just keeps getting better... Since my last post on this thread I bought a Scangauge II.. What a top piece off equipment it is..
Anyway I done my last trip to Brisbane, and for the overall week/tank, I recorded 8.3lt/10o...... Individual trips to brisbane got down to 7.5lt/100, but arvo traffic on the M1, city driving, red lights and car parks, gave me an average off 8.3lt....
Around town is still at 11.5lt/100

Not bad for a dead stock D40 diesel...

Friends,
Nobody appears to be able to achieve the advertised fuel figure with the D40 YD25 AUTO.
Nissan are aware of this as they have many complaints, so much so as to warrant Nissan to issue their agents with a set of stock answers to appease owners who complain.
The YD25 Auto is way behind other manufacturers when it comes to fuel consumption (do your own comparisons where possible).
Nissan should be held accountable. I believe some people have taken Nissan to court over this issue and won.
Rd's
Burgo

I don't know mate, my D40 is a auto and Im getting similar milage to my work partners 2009 Triton, TD, manual.

Totally city driving, i'm getting as low as 7.7l average on some trips from Biggera Waters to Broadbeach.. 17klm and 29 traffic lights ... I usualy average 11.1L to a tank, but that includes towing my boat to the ramp and back.... If I took that out, I would be in the high 9's, low 10's,,, city cycle only....

Buying the Scangauge was the best thing I did to improve the economy.. Not that it inproves the cars economy, it teaches the driver where to ease off the peddle...
The key to good economy is getting the converter to lock and stay locked as long as possible..

Jabba said:

I don't know mate, my D40 is a auto and Im getting similar milage to my work partners 2009 Triton, TD, manual.

Totally city driving, i'm getting as low as 7.7l average on some trips from Biggera Waters to Broadbeach.. 17klm and 29 traffic lights ... I usualy average 11.1L to a tank, but that includes towing my boat to the ramp and back.... If I took that out, I would be in the high 9's, low 10's,,, city cycle only....

Buying the Scangauge was the best thing I did to improve the economy.. Not that it inproves the cars economy, it teaches the driver where to ease off the peddle...
The key to good economy is getting the converter to lock and stay locked as long as possible..

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Jabba,
If your vehicle is the proof then we must ask why nissan can't fix the rest.
I've tried driving mine with cotton wool on my feet and can't get anywhere near 10.5l/100 let alone 7.7??
Nissan themselves could only get 12 5l/100 on the open road when they tested my vehicle and that was light footing it at 90klm/hr.
I can get well under the quoted figure with other vehicles so I know it,s not my driving and I use a boost gauge to help improve the economy the same way a scanguage does.
Nissan should get the specs off your vehicle and apply it to all D40's before they loose too many more sales.
Rd's

burgo said:

Jabba,
If your vehicle is the proof then we must ask why nissan can't fix the rest.
I've tried driving mine with cotton wool on my feet and can't get anywhere near 10.5l/100 let alone 7.7??
Nissan themselves could only get 12 5l/100 on the open road when they tested my vehicle and that was light footing it at 90klm/hr.
I can get well under the quoted figure with other vehicles so I know it,s not my driving and I use a boost gauge to help improve the economy the same way a scanguage does.
Nissan should get the specs off your vehicle and apply it to all D40's before they loose too many more sales.
Rd's

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I don't know why nissan cant fix the rest.. But what I do know is my ST-X is stock standard, it still has the original air filter and I have never added a fuel additive...
My D40 was a total fuel slut when it was new.. 16L was the norm around town and 12l hwy , and that was driving with a light foot.. Since I hit 35'000km on the clock my economy improved out of sight.. I was going to trade the D40 in on a new Trition.... But now I'm having second thoughts...

My usual trip to work today came in on 8.7L and back home was 9.6L as traffic from Broadbeach to Southport was a lot heavier...

Thanks Jabba,
I,m very familiar with the 16 l/100k, and 25l/100k when towing.
The problem must be in the tuning for it to change so rapidly.
Mine has done over 40000klm now, Nissan fitted a new set of injectors at 30000k but that only helped slightly.
Can you remember doing something to the vehicle around the time of change?
Also, have you checked your oddometer, I've been told by a techo that they are prone to play up.
Rd's

Does anyone know what the ADR standard fuel test is, or how it is performed?

08KINGCAB said:

Does anyone know what the ADR standard fuel test is, or how it is performed?

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Have a read thru this and it may shed some light on how it is derived.

http://www.greenvehicleguide.gov.au/GVGPublicUI/StaticContent/ratings.aspx#a

burgo said:

Thanks Jabba,
I,m very familiar with the 16 l/100k, and 25l/100k when towing.
The problem must be in the tuning for it to change so rapidly.
Mine has done over 40000klm now, Nissan fitted a new set of injectors at 30000k but that only helped slightly.
Can you remember doing something to the vehicle around the time of change?
Also, have you checked your oddometer, I've been told by a techo that they are prone to play up.
Rd's

Click to expand...

The odometer is all good..
I have done nothing to the car,, and so far all the services have been done differant mechanical work shops, not Nissan...

As I said, my car today is exactly the same as it was the day I bought it. It literary still has the same air filter in it since day 1...
The change was gradual,, It been improving every 10'000km... The first 5000km I was crapping myself.... I went from a 550hp BA Falcon ute that did the quarter mile in 11.7sec, and only used 10lt/100 on the HWY... To this D40 that was using 14lt/100... I was thinking I was buying an economical work truck, but boy was I wrong....

But like I said the more km I put on the clock, the better it's getting...
Today was not crash hot with the economy.. This morning I was running late, so I had the boot into it a fair bit.. 12lt/100 average to work. And home was bumper to bumper, and I recon I got nearly every red light.. 10.9l/100 to home...

Dead set, Do yourself a favor and get the Scanegauge II.. It'll blow your boost gauge away.. The Scangauge has a boost gauge built in, and it tell you everything that is happening under the hood..
Having the Instant Fuel Economy, Average Economy and Boost all on the screen at once realy helps the driver to drive economically....

You'll be surprised how little input you need with the throttle to blow the economy sky high, and how the slightest throttle adjustment can drop your Instant by as much as 10l/100 and not loose any speed.. That you can not get from just a boost gauge, you need the instant economy...
For $200 the scangauge is a must have for a Auto D40 Diesel

Jabba said:

The odometer is all good..

For $200 the scangauge is a must have for a Auto D40 Diesel

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I agree totally with this statement. Driving to the Scangauge certainly helps me keep the fuel consumption down althought I don't get anywhere near as good as Jabba.

I have done a lot of mods and probably weigh a good few hundred kilos more than a stock vehicle. I also have BFG A/T tyres which I reckon would have a higher rolling resistence than the stock HT tyres.

I get around 11.5 - 12.5 around town unladen...ie that is still with the winchbar, winch, towbar and hitch, full set of bash plates, a large ORS storage unit, 2 x 105AH aux batteries,70 ltr ss water tank (empty), ARB canopy, always carry a bag of tools and my recovery gear, and I have a 160ltr OL long range fuel tank. When on a trip and with the drawers and fridge fully stocked and the water tank full I get around 13.5 on the highway.

I recently did a 19000km trip crossing Aus via the Nullarbor East to West into strong winds, and returning through the middle via the Kidson Track, Wapet, Gary, Gunbarrell, Heather Highways, the Great Central Road and then a crossing of the Simpson Desert from West to East....for this trip I averaged 14 ltr/100km. In addition to all the stuff in the back and the aftermarket stuff I had a jerry can, gas bottle, 2nd spare, and the Oztent on the roof - so all in all like driving a block of flats through the air. So I reckon that 14 was a pretty good result.

Cheers
Pete

Pete

What sort of weight would you estimate you were carrying in all that load?

I'm doing the Nullabor trip in a few weeks and even loaded with what I estimate to be about 650kgs on the back axle I'm hoping to get heaps better than 14's.

I imagine your trip home would have increased your average a bit given that it's not the flat bitumen track the Nullabor is but still I'd be hoping the winds weren't strong enough to push me out to 14's.

Have you got separate figure for East to West that you can compare to the West to East figures or was the overall trip the only one you calculated?

KraftyPg said:

Pete

What sort of weight would you estimate you were carrying in all that load?

I'm doing the Nullabor trip in a few weeks and even loaded with what I estimate to be about 650kgs on the back axle I'm hoping to get heaps better than 14's.

I imagine your trip home would have increased your average a bit given that it's not the flat bitumen track the Nullabor is but still I'd be hoping the winds weren't strong enough to push me out to 14's.

Have you got separate figure for East to West that you can compare to the West to East figures or was the overall trip the only one you calculated?

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Krafty - I reckon I was at or slighty over my max payload - guessing around 900kg. Unfortunately the trek across the Nullarbor was a pretty thirsty one as for two days we were punching into a westerly that was ranging between 40 and 60 kph. My fuel consumption on the worst day was 18 LPH but was pretty good relative to some other travellers I spoke to. A guy with a Troopy RV 4.2td with a Howling Moon rooftop tent told me that he couldn't hold 5th gear and was returning around 20 LPH. Another guy in an older Rangie V8 said he had to switch to petrol as he couldn't get better than 40kph on gas. On petrol he said he returned about 26 LPH. Another guy with a 100S cruiser 4.2tdi was pulled up at a rest stop and he told me that he was staying put .....he reckoned that the wind was at least a "2 slabber" - ie he could stay and have a few beers and pay for 2 slabs from the money he would save by not driving into the wind. After this trip my next journey across the Nullarbor will be a West to East one. The attached pic was taken on the morning we departed Smokey Bay and this wind didn't let up for a few days.

Can certainly recommend the caravan park at Smokey Bay - it is superb, reasonably priced, great camp kitchen and the best damn oysters anywhere. Also....try to make it to Eucla to refuel....about 3km off the highway but 11 cents/ltre cheaper than the BP roadhouse at Border Village.