Outer Limits 4x4 Board

hey fellas, thought i might pass it by u guys before i actually go speak to my mechanic

Up until a month ago, id never really done a whole lot of highway kms, so driving around the city i found i was getting a constant 600kms out of the tank..

The last month ive been working down the coast, and its included doing around 1200kms a week, basically all highway kms ranging from 80-100km/h zones..

But my fuel is only just lasting me around the 600km mark.

So my question is, this been my first diesel vehicle, do they not get a longer km range from highway driving? If yes, what could be causing the lower kms?

usually around 10l/100km for us. tho we have lots of little hills and twisty roads.

actually milage depends on lots of things, tires, tire pressures, wind, vechile load, quialty of fuel, actual speed, style of driving etc. it really starts sucking the gas above 100km/h.

a few things you can do to help economy, block EGR, disable EGR butterfly, have a clean air filter, big bore exhaust, good oil, good fuel filter.

truck was serviced 3 weeks back, although the airfilter hasnt been replaced for around 12 xxx kms (service before last)

its a stock navara at the moment, and i run 45psi in the tires, but there has been a bit of sitting on 110 i guess, that could be the reason for it..

pull the air filter out and check it. they have a nasty habit of leaving dirty ones in there. if its dirty, especially oily, throw it and fit a new one.

also while your at it (pays to pull the intake hose off the turbo when checking filter) see if there is any oil sitting in a puddle in front of the turbo. if so (highly likely) then you need to fit a decent catch can that has filtering medium (eg stainless wool) inside it.
that oil in the intake gets burnt and that extra bit screws the ECU up a bit as it has trouble relearning fuel flow etc.

also with a stock vehicle DO NOT do more than 10,000km without changing oil. depending on oil that your using i would recommend 5000km oil changes.
i did the oil change on the bosses ute @ 13,000 km and it was like treacle (and that was with commercial long run CI-4 grade oil).
if the oil is full of crap it won't cool the pistons properly and you can blow holes in pistons (just like a patrol!)

ah k sweet as dude, thanks for the info..

im lucky that the mechanic is a good family friend and he also drives a jacked up patrol so he knows his way around the ZD30..

Airfilter was certainly changed back then, cause i had to do it lol

put it on a diesel gas australia system you will pick up aprox 20% more ecconomy 20% more torque and 20%more power

Yep, I get much better economy at 90-95 than I do at 100 - 105

I get 1000km's out 105L of diesel, 2006 STR Navara. 70,000km's on the clock.

Usually sit on 110km/h on the New England Highway, I have a snorkel and a fair few accesories and I think the ute would be around 2100kg or abit more.

Thinking of getting an exhaust soon aswell.

Best truck I have ever owned.

dave_str wrote:
Thinking of getting an exhaust soon aswell.

highly recommended

yeah i find if i go over 100k's it really starts to drain the diesel. if i stay on 100 when on the free which is as fast as im allowed to go anyway i get atleast 640k's out of the tank n thats with a mix of city/freeway/offroad.

yeah cheers mate, guess its just the way it is then haha..

Bit of a bummer i guess