Unhappy with my milage

[Jrgd40]

Hi all,
I have an auto D40 with 140k.
Only mods that I know of (only owned the truck for a month or so)
are canopy, on board diesel/water seperating filter, oil catch can.
Nil towing, around town kms I'm only getting 14.4L/100
I'm pretty disappointed with this really, considering I get this out of my Mazda CX9 which are renowned for being thirsty as f$#k. I used to get that out of a vxss 5.7 gen 3 also.
The thermos seem to run too often in my opinion.
Would anyone out there have any suggestions of things to check out in order to improve the mileage?
Or is this considered normal?
I'm starting to think I should have just gone with the 6cyl option!
Could a dirty EGR cause this issue?
Thanks for any help in advance

 

[jonney]

you should be getting around the 9 to 10 l/ 100. has the engine had the fuel filter and air cleaner changed recently.? also you might need to do an ECU reset as the ecu might be sending too much fuel to the injectors/ pump.

 

[Jrgd40]

Thanks Jonney, these are places to start checking I guess!

 

[jonney]

yes i would start with a new fuel filter and aircleaner then re set the ecu. not sure if you have to get a mechanic to do the ecu re set / re learn . a mate recently had bad fuel economy with his nissan patrol until he took it to nissan and they did the re-set then all was fine after that.

 

[Old.Tony]

It depends on the model of engine too.

126kW (up to early 2010 STX, all RX and Thai ST models) should get around 12LPHK around town and 10LPHK on the highway.

140kW (mid 2010 STX onwards) should get around 9-10LPHK around town, with reports of 8LPHK on highway.

Fuel economy is affected by quite a number of things. How large your foot is, for example. Low tyre air pressures increase fuel consumption. Finding a Hilux (with an engine that's actually running) at the traffic lights is a major contributor to poor economy. Turbocharger issues can impact on it, as can a dirty intercooler, dirty intake manifold, excessive EGR, inadequate boost control, dirty MAFS ...

You can do the following (none of them will hurt the vehicle, some might cost a LITTLE but nothing extravagant):

1) Block the EGR valve. If your car is from late 2010 onwards, you'll have to have a 6mm hole in the middle of the blanking plate.

2) Clean the MAFS. It's in the back of the air pipe just outside the filter box. Be careful with it, remove it and spray electrical contact cleaner into the small hole near one end. Do NOT poke anything into the hole, no matter how tempted you might be. It's $400 tossed out if you do.

3) Clean the intercooler. Remove the grille, undo the hose clamps on each side, two bolts at the top and pop her out. Hold your hand over one opening, pour unleaded petrol in the other, then give it a good shake, releasing the UPPER hand every now and again to let the pressure out. The intercooler will cause the fuel+vapour inside to expand. Rinse and repeat until the fuel coming out is starting to show signs of its actual colour - mine took 5 goes before you could see more than just black.

4) Measure the boost levels. A $5 eBay purchase of a ELM327-compliant Bluetooth OBD II adapter and a free app on an Android phone will let you do this. Pay for the app (it's like $5 or so as well) if you feel good about it. If you're not boosting in moderate acceleration to about 18psi then your turbocharger is underperforming and this might cost a bit to fix. If it's not performing much at all, it could be vac hoses and 3m of 3mm vac hose will set you back about $20 at most auto spares shops. Remove a piece from the car, cut a replacement, install, move on to the next one and don't let anyone interrupt you so that you forget where each end goes.

5) Buy a can of Liqui Moly Fuel System Treatment and pour it in your tank. You should notice a difference after about 100km. If not ...

6) Buy a can of Liqui Moly Diesel Purge and follow the destructions. I'm about to do this one myself, I've noticed that my fuel rail pressure is dropping markedly under higher acceleration levels so I suspect my SCV needs some "special care".

7) Remove your SCV, wash it in petrol, rinse it in fresh diesel and reinstall.

Just a couple of things to try!

 

[Ozzyeureka]

D40 fuel usage

Quoting fuel usage figure is a pretty random thing, especially city rates. If you are in Sydney and commute then your fuel usage will be abysmal, Melbourne, not much better, Adelaide - what's peak hour?, Perth - depends on if you are north /south, or coming in from the east.

In Sydney commutes my fuel burn can easily run to 18l/100km on a long term average (6 months from fuel dockets/distance) I work on about 500kms to a tank, with air con on most of the time.

Country driving I get closer to 11-12L/100km.
My nav is a D40 Spanish built Yt25 auto , 2007 model , stock tyre diameters, empty tray most of the time and cab is pretty clean ( about 20Kg made up of recovery gear, first aid kit and some tie downs) . 276000Kms on the clock.

If I put the boat on I get to 15-16l/100km ( 700kg boat and trailer, and usually Mt Ousley is on the path) .

I am an off road tourist these days, I don't go for the harder paths so off road fuel usage is about the same as towing the boat.