I used electrical contact cleaner (about $9 from Jaycar). I removed the MAFS from the air intake and sprayed the contact cleaner inside it while ensuring that none of the spray or the excess went into the intake tube.
D40 Fuel Economy
- Thread starter Dazza
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I used electrical contact cleaner (about $9 from Jaycar). I removed the MAFS from the air intake and sprayed the contact cleaner inside it while ensuring that none of the spray or the excess went into the intake tube.
snarzy
Member
Excess fuel consumption.
Hi, I am getting absolute max 500ks from 64 ltr tank. 2008 d-40 auto turbo diesel. What are others getting ? What can I do to improve fuel economy ? Any suggestions? Am thinking of putting a hho kit in , has anyone installed one of these kits?
Cheers and hope I can get some help.
Snarzy
I recently had a winge to Nissan about the fuel economy of my 2008 2.5 auto diesel Nav D40. Response I got was "Checked fuel consumption figures provided by customer 14l/100kms is within average range for vehicle. Checked for fault codes in system - none evident. Reset pump relearn clear, tested, all OK." Well whatever they did by resetting the pump etc worked....after 2 x trips in excess of 500km each I am now getting 10.4l/100kms - happy with that. I guessing I will see a rise in that over the coming weeks as my canopy, storage syste, lift and 160ltr fuel tank are installed
Hi, I am getting absolute max 500ks from 64 ltr tank. 2008 d-40 auto turbo diesel. What are others getting ? What can I do to improve fuel economy ? Any suggestions? Am thinking of putting a hho kit in , has anyone installed one of these kits?
Cheers and hope I can get some help.
Snarzy
K
KraftyPg
Guest
I came home from Melb loaded with furniture and shit last weekend and got the 160 odd ks home on 8.7lph, the rest of the tank has been back to my average of mid 9's since getting home.
That is impossible for anyone on the internet to answer accurately. This thread and the other economy threads will give you many different suggestions and many different methods that others are using however what it can't give you is the exact efforts others are making. I can tell you taking it it easy on the throttle is one thing which gets me good economy and you can say you already do that but there is no actual comparison between our methods making it hard to compare anything.
At the end of the day you're trying to move a 2 tonne wind break (with or without mods that could add to economy figures) with a 5 year old motor that the manufacturer probably didn't guarantee much below 11lph for when it was new. Your biggest and cheapest improvement will probably come from your right foot and that mushy blob inside your head that dictates how you should drive.
Welcome to the forum!
As posts like those from Daveo prove, and as Krafty says, it's difficult to say what causes poor fuel economy but there are things that you can do - and know - that can help.
1) Speed kills. Why? Your engine produces its maximum torque at 2,000rpm and that's about 95 km/h in top gear. Any slower and your turbo isn't producing enough boost. Any faster and the rate of fuel input is rising much faster than the rate of power output = wasting fuel.
2) Most of your fuel is consumed in getting the vehicle up to speed. Once at cruising speed you only have to maintain it. If you spend most of your time in traffic, you should never expect good fuel economy from a heavy vehicle.
3) In a similar vein to 2), diesels work differently to petrol. They react well to allowing the engine to bring the vehicle up to speed rather than just hammering it - taking off fast might be cool up alongside a Toymotor, but that's not the most efficient way of using a diesel. Diesels probably shouldn't be owned by impatient people!
4) Aerodynamics. Krafty's right - the Navara (any ute/van) is essentially a brick with wheels. Bricks might travel through the local politician's window with relative ease but out on the road with wheels beneath it the wind resistance starts to kill it at cruising speeds and this increases exponentially as the speed rises. As an example, the Lockheed SR71 flies with a surface temperature of ranging from 200C to 600C - all from resistance. Crews of the SR71 would hold their meals against the glass to heat them up (source here, and here). To heat the air like that - just passing over the surface - requires energy, and lots of it. And the Navara is a lot less aerodynamic than an SR71!
Now, with all that said, your 2008 auto is getting about 12.8LPHK which is not unreasonable. Larger tyres than standard (255/70R16) will add about half to one litre used per hundred km. Not blocking the EGR will cost you about half a litre per hundred km. Having gunk in your intercooler, dirty air filters etc will all exact a small price in consumption.
Hope that helps!
Pete22
Member
Welcome to the forum!
As posts like those from Daveo prove, and as Krafty says, it's difficult to say what causes poor fuel economy but there are things that you can do - and know - that can help.
1) Speed kills. Why? Your engine produces its maximum torque at 2,000rpm and that's about 95 km/h in top gear. Any slower and your turbo isn't producing enough boost. Any faster and the rate of fuel input is rising much faster than the rate of power output = wasting fuel.
2) Most of your fuel is consumed in getting the vehicle up to speed. Once at cruising speed you only have to maintain it. If you spend most of your time in traffic, you should never expect good fuel economy from a heavy vehicle.
3) In a similar vein to 2), diesels work differently to petrol. They react well to allowing the engine to bring the vehicle up to speed rather than just hammering it - taking off fast might be cool up alongside a Toymotor, but that's not the most efficient way of using a diesel. Diesels probably shouldn't be owned by impatient people!
4) Aerodynamics. Krafty's right - the Navara (any ute/van) is essentially a brick with wheels. Bricks might travel through the local politician's window with relative ease but out on the road with wheels beneath it the wind resistance starts to kill it at cruising speeds and this increases exponentially as the speed rises. As an example, the Lockheed SR71 flies with a surface temperature of ranging from 200C to 600C - all from resistance. Crews of the SR71 would hold their meals against the glass to heat them up (source here, and here). To heat the air like that - just passing over the surface - requires energy, and lots of it. And the Navara is a lot less aerodynamic than an SR71!
Now, with all that said, your 2008 auto is getting about 12.8LPHK which is not unreasonable. Larger tyres than standard (255/70R16) will add about half to one litre used per hundred km. Not blocking the EGR will cost you about half a litre per hundred km. Having gunk in your intercooler, dirty air filters etc will all exact a small price in consumption.
Hope that helps!
Well said that man!!
Kingy89
Member
Well said i was getting roughly 650 to a tank stock as a rock nav then block the EGR and immediately got another 100 or better out of a tank then i put a chip on the vehivle and it has dropped back to about 680 700 to a tank but in saying that it is set of the highest perforamce setting possible
last tank i got 780km's from 68ltrs.. This tank is even better, gone 730km's & the trip meter is saying around 130kms left in the tank.
Both tanks did have 500kms of highway driving at 105km/h.
2012 man 13,000kms on the clock now.
Both tanks did have 500kms of highway driving at 105km/h.
2012 man 13,000kms on the clock now.
Munnerz that's about 13.7 LPHK. For city driving that's not bad - I'd probably expect a little better from a 2012 model but I have to remember that it's city - start, stop, start, stop and that's where most of the fuel is going to be used.
We just put new tyres on ours - we had BFG ATs 265/70R16 and I went back to 255/70R16, which was the standard size for my model. The car feels like it's not as loaded, and climbs hills easier - so the 2% difference does make enough of a change to be noticed. I'll be filling it tomorrow - no point worrying over the economy figures, there was a service, some towing and most of it on the old 265s, but I bet I'll see an improvement on the next tank (refilling about every 3 weeks) so I'll report back after that tankfull.
We just put new tyres on ours - we had BFG ATs 265/70R16 and I went back to 255/70R16, which was the standard size for my model. The car feels like it's not as loaded, and climbs hills easier - so the 2% difference does make enough of a change to be noticed. I'll be filling it tomorrow - no point worrying over the economy figures, there was a service, some towing and most of it on the old 265s, but I bet I'll see an improvement on the next tank (refilling about every 3 weeks) so I'll report back after that tankfull.
Yeah I'm not that stressed about it, I fill up once a month so it's not to bad, I just here other ppl quoting low 10s and 9s and makes me wonder lol.
Thanks for the info
Black_Outlaw
Member
Wow - what a great thread.. Learnt quite a bit.. It seems I have to:
1. Lay off the BOOST..
2. Clean my Intercooler (190,000km would equal a shirt load of gunk - and loss of efficiency)
3. BLOCK My EGR..
4. Clean my Intake
5. Clean my MAFS - which I have done... It was BLACK every little bit of it.
6. Lay off the BOOST
7. Get rid of my DPF...
8. ECM Reset...
1,3,4,5,6,7,8 seem easy.. Cleaning the intercooler might take a bit of nuttin out..
I think I might also replace my piping from turbo to intercooler as the rubber hose BULDGES something shocking when giving the engine a rev...
Cheers...
1. Lay off the BOOST..
2. Clean my Intercooler (190,000km would equal a shirt load of gunk - and loss of efficiency)
3. BLOCK My EGR..
4. Clean my Intake
5. Clean my MAFS - which I have done... It was BLACK every little bit of it.
6. Lay off the BOOST
7. Get rid of my DPF...
8. ECM Reset...
1,3,4,5,6,7,8 seem easy.. Cleaning the intercooler might take a bit of nuttin out..
I think I might also replace my piping from turbo to intercooler as the rubber hose BULDGES something shocking when giving the engine a rev...
Cheers...
Last edited:
ferral 666
Member
2012 ST 10000k on clock ... Getting 9.1 at the moment. Got down to 8.8 , then up to 9.2 cos I towed a staircase ( nearly a ton ) up Mt. Buller
2010 Dual cab st tdi auto. 35k since new , back at nissan again for excessive fuel con they performed an economy test and got 18.8 LPH and now are tring to tell me its because of the bull bar and bfg ats.
Once again ,thanks Nissan for backing up your product.
Once again ,thanks Nissan for backing up your product.
K
KraftyPg
Guest
Fcuk that must be one heavy bullbar
K
KraftyPg
Guest
The biggest problem with economy is that there is no magic figure a vehicle must attain. The figure on the window when you buy a car is there for government regulations only and not because that's what they expect the car to achieve.
I agree that 18's is high and there is definitely something strange happening, although many 09/10 model KC's got such figures with no explained reasons.
If I was you I wouldn't take the 'mods' excuse too seriously, flip it over and take it as "we don't have a f'n clue". It's still not easy to accept but it's easier to except than just thinking these so called experts are looking to palm you off, because they would no doubt love to charge you for a fix if they could but not being able to find that fix is stopping them.
It might cost you but maybe consider taking it to a diesel specialist and see what they suggest.
I agree that 18's is high and there is definitely something strange happening, although many 09/10 model KC's got such figures with no explained reasons.
If I was you I wouldn't take the 'mods' excuse too seriously, flip it over and take it as "we don't have a f'n clue". It's still not easy to accept but it's easier to except than just thinking these so called experts are looking to palm you off, because they would no doubt love to charge you for a fix if they could but not being able to find that fix is stopping them.
It might cost you but maybe consider taking it to a diesel specialist and see what they suggest.
The very first thing I'd do is get a second opinion. And I'd start with the figures used to obtain the economy results. If you could fill up, reset the tripmeter, drive around for a few days and refill and tell us how many litres and how many km we can be stunned by the raw data just like you!
Then some other answers are going to help too. The more accurate your answers, the more accurate the responses.
1) How much throttle do you use to accelerate normally?
2) While accelerating from a standing start, what RPM do you typically reach?
3) Do you shift manually, or just have it in 'D' with the overdrive switch so that overdrive is NOT off (the light on the dash is NOT lit)?
4) What is the exact size of the tyres on your car (eg mine are 255/70R16)?
Then some other answers are going to help too. The more accurate your answers, the more accurate the responses.
1) How much throttle do you use to accelerate normally?
2) While accelerating from a standing start, what RPM do you typically reach?
3) Do you shift manually, or just have it in 'D' with the overdrive switch so that overdrive is NOT off (the light on the dash is NOT lit)?
4) What is the exact size of the tyres on your car (eg mine are 255/70R16)?
sevenmile7
Member
My tyres are 265-75-16 which almost corrects the speedo but puts the odometer out nearly 10%. I'm sitting around 12-14 in my 6sp man. I can't seem to get it any better, idle is a bit rough and has bullbar & muddies. I'm at the fuel bowser a fair bit more when towing farm gear and paddock work. Had to fill up at 300km towing a 2 tonne spreader in hilly sand paddocks in 4wd. I think I've gotta get my injectors looked at.
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