D40 Fuel Economy

Nissan Navara Forum

Help Support Nissan Navara Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
I haven't, and won't. I think the safest way to protect the ECU and still drain the power in a short period of time (seconds) is to remove the battery leads from the battery, then turn on the ignition. It should have the same effect as removing the power cord and motherboard battery from a computer then turning it on: all of the power should discharge internally through normal means.

The ECU reset should be achieved without risking any component failure.

Just remember to note down trip km, if you record that information for fuel usage figures.
 
Ok there is a difference between the airbags reset where the firmware itself was upgraded so the airbags went off earlier in the case of an accident as far as I know.
In theory it should only have been an upgrade to the firmware of the airbag module itself( yet another ECU ).
The odometer etc will not be reset as far as distance travelled on the truck.The mileage on the tank itself ( trip computer )to be honest I cant remember if thats reset or not but I think it is.Never took that much notice as I use the Scangauge to do all the real readings.
Marty when you try this can you put a multimeter across the terminals and see if you get any voltage .
If some are worried about doing damage as I can see some are then get a small wattage globe say 5watt or less ( the smaller the better ) and connect that across the terminals . If there is any residual capacitance then the low wattage globe will discharge anything slowly.

Now the guys in the US have been doing this for a while without any reported issues

Marty it was my incoming engine air temp that was reading high when I changed filter. The engine itself was cold as I left it to cool over night and then did the reset so it was a full and proper reload of everything

Like I said DO NOT DO THIS if you have any smoothing capacitors for your stereo as that will have a large charge and this will cause a spike .
 
Ok there is a difference between the airbags reset where the firmware itself was upgraded so the airbags went off earlier in the case of an accident as far as I know.
In theory it should only have been an upgrade to the firmware of the airbag module itself( yet another ECU ).
The odometer etc will not be reset as far as distance travelled on the truck.The mileage on the tank itself ( trip computer )to be honest I cant remember if thats reset or not but I think it is.Never took that much notice as I use the Scangauge to do all the real readings.
Marty when you try this can you put a multimeter across the terminals and see if you get any voltage .
If some are worried about doing damage as I can see some are then get a small wattage globe say 5watt or less ( the smaller the better ) and connect that across the terminals . If there is any residual capacitance then the low wattage globe will discharge anything slowly.

Now the guys in the US have been doing this for a while without any reported issues

Marty it was my incoming engine air temp that was reading high when I changed filter. The engine itself was cold as I left it to cool over night and then did the reset so it was a full and proper reload of everything

Like I said DO NOT DO THIS if you have any smoothing capacitors for your stereo as that will have a large charge and this will cause a spike .


Drum Roll thanks :big_smile:

Ok I drove the Nav for 30 k's this morning to get everything up to working temps , disconnected the battery and tried two things , one was Tony's way and the other was Ausssie's.
When the battery was disconnected the voltage stored in the system was 11.64v , thinking that might be a little high for the terminal discharge I decided to use Tony's method, with the battery disconnected I hit the ign key and turned her over , and yep you guessed it, click and that was about it.
Next recheck the voltage - big fat Zero and just to make sure I now earthed the leads together and still big Zero.

Restarted the engine and everything run smooth , Phew glad about that one as I was worried if the ECU wipe would require the Injectors to be recoded , happy to say they didnt.

Got in it and drove out the driveway I thought it was pulling better than before , nah must be imaging it goes better

During the day I drove as per usual and there has always been one section of road that let me know if the LPG is working or not, the normal scan gauge reading at best would be 8.1LHK not this time as it read 6.9LHK. Yeah sure you say , well lets put it this way I have not had these sorts of readings for a F@#$@ng long time. Ok I said I must have reset the scan gauge wrong, nope I checked and rechecked and it was set correctly with the setting I had written down before.

Next test was a long drive with lots of hills , some flat sections and more hills, at the end of a 130k drive my reading were far better than ever before, try 7.4LHK , remember I run Diesel with LPG so one would think the figures would be lower and I honestly feel that the Vehicle is back to what it used to be like so many km's ago ((try some 100'000km's ago))

Time will tell if I'm dreaming or if indeed something has been cleared from the ECU that had made the pump richer so to speak all this time, put it this way I have never been able to drive in 6th gear at 90km/h with the reves just under 2000rpm and still being able to pull out of it with ease.

I will do a full refuel tomorrow , diesel 150L and gas 50L , Zero the scan gauge and it about 3 weeks time I will know for sure, but for now I'm tickled pink and the spark the Nav had to begin with has returned fingers crossed

I must add , in the past when I used to carry out the pedal clearing sequence I had always done this with the engine being stone cold , and it now makes me wonder if indeed the ECU read and set the fuel mixture accordingly, this being cold and not hot like this time round

If this has really done the trick on my Nav, I wont bother with the Pedal crap anymore and just do the stored voltage wipe from now on

Cheers Marty
 
Hey Martinsd40, when you say you earthed the leads together did you just touch the 2 leads together without been connected to the battery at all? also do you guys think that this is a better way of preforming a complete reset of the ECU?

thanks
 
What Martin did was disconnect the neg lead off the battery then turn the key in the ignition to discharge any residual power. Once thats done just reconnect your neg lead to your battery. Full reset done.
 
Ok just a little more info from a Navara UK Forum
The sequence of the ignition and throttle etc sets the ECU into learning mode doesnt reset it.Thats where the difference comes in. In learning mode it just relearns the parameters however a full reset actually reloads the firmware.
 
Hey Blokes - an update on fuel consumption 2010 D40 TD 4x2 - I posted figures a couple of weeks ago for country run of 9.2 ish and have just filled up the next tank which has been all city driving and managed 10.9. Fuel light came on w-approx 15 L to go. As previously stated I do drive pretty conservatively. I especially dislike wasting fuel on A/C. I have just dropped tyre pressure from 35 to 30 also as the ride was too hard for me so no doubt will impact on fuel also
 
I drive conservatively enough that Miss Daisy would tell me off for going to slow but if it's hot I'm not leaving the A/C off just for a little bit of extra fuel and in mine it's bugger all.

While the scangauage is really only as accurate as you want to make it and it works on averages and it's figures can be as widely influenced with many small keying errors over time as it can be with one huge error in one hit etc etc the scangauge reading on mine shows very little effect on the car with the A/C running.

Being a Victorian I don't need an A/C that often but heading to Perth last year we went through several days of mid 40 temps. I only ever use the A/C and fan on 2, it might take a little longer to cool the car but it still does it and we can be comfortable in the car within a few minutes even after the car has sat in the sun for a few hours. Being the first big trip I'd done with both the Nav and the scangauge I was keeping a good eye on things and with the A/C on and the fan on 2 the rev's increased by between 30 and 70 (or thereabouts) RPM and on dead flat road with cruise set at 97ks the LHK flactuated at the same or very similar rate that it did under normal driving conditions without the A/C on. Sure it picked up 0.1 or 0.2 here and there but it does that on any road because it's working on averages not real time calculations.

So as far as being conservative and not running the A/C to save fuel for the minuscule amount mine uses I'd rather be cool and spend a few extra cents. Interestingly enough on the hottest day where outside temps peaked at 45 at 4pm I still got better economy that day than I averaged over the whole trip to and from Perth.
 
Gday, are you sure your calculating your fuel economy correctly? When my light comes on i have about 12litres left in the tank & currently getting about 650km which works out to be roughly 10.6L/100km. I'm driving a 6spd manual diesel?? Mine is slowly getting better. If you getting that from an Auto your one in a million...

Hi Wayno, sorry if this comes out wrong, but you did well getting the 6sp, I got the auto and at the moment I am getting 15-16lts/100ks highway cycle or a touch over 500ks to a tank and I fill until I can see the fuel at the top of the thread. Dam particulate filter(which I have been told no other dbl cab maker uses), but I am slowley changing this problem.Installed a chip, which gave it more NUTS, which it didnt really need(more NUTS is always needed), but I just picked it up from Beaudesert Exhausts, after 3weeks R&D, and although I have only just put a new tank of diesel in it, the last quater of the previous tank was spent with beaudesert exhausts, and it showed an extra 50ks. So I am hoping to get close to the returns that you are getting
 
Hi Wayno, sorry if this comes out wrong, but you did well getting the 6sp, I got the auto and at the moment I am getting 15-16lts/100ks highway cycle or a touch over 500ks to a tank and I fill until I can see the fuel at the top of the thread. Dam particulate filter(which I have been told no other dbl cab maker uses), but I am slowley changing this problem.Installed a chip, which gave it more NUTS, which it didnt really need(more NUTS is always needed), but I just picked it up from Beaudesert Exhausts, after 3weeks R&D, and although I have only just put a new tank of diesel in it, the last quater of the previous tank was spent with beaudesert exhausts, and it showed an extra 50ks. So I am hoping to get close to the returns that you are getting

Also it's worth checking your odometer, mine is out by 10%, so you could be getting closer to 600k's a tank.
 
Hi Wayno, sorry if this comes out wrong, but you did well getting the 6sp, I got the auto and at the moment I am getting 15-16lts/100ks highway cycle or a touch over 500ks to a tank and I fill until I can see the fuel at the top of the thread. Dam particulate filter(which I have been told no other dbl cab maker uses), but I am slowley changing this problem.Installed a chip, which gave it more NUTS, which it didnt really need(more NUTS is always needed), but I just picked it up from Beaudesert Exhausts, after 3weeks R&D, and although I have only just put a new tank of diesel in it, the last quater of the previous tank was spent with beaudesert exhausts, and it showed an extra 50ks. So I am hoping to get close to the returns that you are getting

I've got an 07 auto (with DPF) and I average around 11L/100km open road (cruise control set at 110kmph) and 12.5L/100km around town. I carry approximately 600kg in the back and have no after market bits on it at present as until recently it was still under warranty. Gets serviced every 10k and is only on it's third factory air filter at 108km (my dealer changes them at 40k intervals).
The best return I've had was 9.95L/100km open road with no hills and bugger all traffic.
Even towing half a ton I can still return mid to low 12's (cruise set at 100kmph).
Offroad work I also return mid 12's most of the time.
 
Last edited:
When you are checking your odometer, don't rely on the speedometer to gauge the odometer's accuracy. The two devices are not interlinked any more.

Take your car to a test length on a freeway, set your 'B' trip meter to zero and travel the 5km.

I found that while my speedometer was reading under by about 10%, my odometer was spot on.

Also, just on your economy Duck, I was getting similar figures until my engine reached 13,000km then it started to drop. Here's how you should figure out the EXPECTED economy figures:

Weigh your vehicle. Divide this by 1980. Multiply this answer by 10.5 to get your expected average economy figure.

Mine's 12.2LPHK and when my vehicle was new, I was getting 15's and 16's. I'm now getting 11's (when I am not towing). No chip, no exhaust, no mods.

I'm a fairly conservative driver though - I don't put the boot in at every set of lights, and I'll let the car slow itself as it climbs a hill. I am not in a rush to get anywhere (especially my own funeral) so I just take my time, and that does reflect in better economy.
 
just put 265/75 bfg muds on my d40 auto diesel and uses at least 15l/100 used to do around 11l/100 before anyone else using this much??? seems down on power aswell
 
Zaneo, you've got two things against you with the larger tyres.

First, your odometer is *under* reading your mileage, so you're actually doing more km than you think.

Second, with a larger diameter wheel, you've effectively changed the final drive ratio - the engine has to work harder to turn the wheel over, because of the larger diameter. More force required = more fuel used. This will also feel like a power loss. Just think of it like this: imagine the car, before the tyre change, if you drove it one gear higher than you should have - start off at the lights in 2nd, shift into third too early, etc. That's sorta what the bigger tyres do.
 
I don't think it'll do any damage, the flashing is a message to the Nissan techs that indicate a code that they need to pay attention to. 10 flashes might be "operation incomplete" or "Christ on a Bike the beer's warm!" for all I know.

Turning it off or on and interrupting the sequence was probably the best thing. Try it again and see what happens. Mine didn't work first time, the timing is a little important.

are you guys talking about diesels
 
When you did your original consumption figures you were reading a speedo that reads under the real speed and an odometer thats just as accurate.
Now that you have the bigger tyres your speedo will now read closer to the real speed but your odometer will still be out. What you really need to do is take your readings via a GPS to get the real figures and from that your real economy.

Yeah what the guys are talking about is putting the ECU back in to Learn mode . This effectively will set your economy back to decent again by resetting the ECU's learned data.
If you read back in the earlier pages you will see what we are yammering about .
 
I have 2005 Diesel 6 speed, I do alot of Highway driving and i am getting best - 7.5 to 8.2 Litres per 100 k's - or 1000 km out of tank

I am happy:rock:
 
I have 2005 Diesel 6 speed, I do alot of Highway driving and i am getting best - 7.5 to 8.2 Litres per 100 k's - or 1000 km out of tank

I am happy:rock:

That's great economy, how many k's your truck done? and has the economy improved with time?
 

Latest posts

Back
Top