D22 Fuel usage seems high?!?

hey guys,

i have a 2006 ST-R 3L. It has a steel tray, steel bull bar, warn winch, 2" lift, 265/65/16 MTZ's, fitted with a tunit chip and genuine nissan snorkel. stock exhaust and engine.

out of a full tank of diesel i get about 480k's to light on.

90% road driving, its the missus daily.

is that normal? a fella i spoke to with a stock 07 st-r gets about 700k's out of tank?!?

thanks.

Yep thats bad. Sounds like you've a bit of weight on & those tyres wont help. Biggest factor is how you drive. Be honest now, does the boss have alead foot? Also, how do you calculate your usage: sounds silly but you'd be suprised.

Steel tray wont help, My tray is wider than the body so more wind drag= more fuel, Be guessing yours would be similar, and a chip

Nakedape, im just going off the trip computer. We always reset it when we fill up and only get 450 - 500 k's. She drives ok. Might be a bit heavy on the foot but not too bad.

I figured the tyres would alter the usage a bit but they were on it when i bought it so i have no previous comparison.

As for the tray, d22dave, it does stick out a little. And i thought the chip was supposed to improve fuel consumption?

I had it tuned not long after i got it and the guy said he set it for the best balance of power and fuel ratio as it was a bit rich beforehand.

Help!

chvrl-8 said:

Nakedape, im just going off the trip computer. We always reset it when we fill up and only get 450 - 500 k's. She drives ok. Might be a bit heavy on the foot but not too bad.

I figured the tyres would alter the usage a bit but they were on it when i bought it so i have no previous comparison.

As for the tray, d22dave, it does stick out a little. And i thought the chip was supposed to improve fuel consumption?

I had it tuned not long after i got it and the guy said he set it for the best balance of power and fuel ratio as it was a bit rich beforehand.

Help!

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U have never mentioned how much fuel u put in for those kms travelled.... U need to work out the kms travelled for the fuel used to get an accurate figure. On my vehicle that has a LR tank, I get 600kms and it still reading 3/4 full at 1/4 full on the gauge I've done 900kms, but when I work out the economy I should be getting 1200kms to a tank, which means when the tank is reading 3/4 full, I've actually only got a 1/2 tank of fuel left....

U need to record fuel used vs kms travelled to get and accurate picture of whether your using too much or not.....

480k's to the light on is around 65L, which is terrible economy, somewhere around the 13l/100 mark, even my behemoth doesn't go that bad. Everything will add to your fuel usage;
the loud pedal, the roof rack, the hubs being locked, the tread pattern, the suspension lift, the tyre size (smaller tyres = higher revs = more fuel used) oils, fuel and air filters, snorkel, EGR, chip.

I'd start with driving style. Be more gentle with how you drive the ol' gal, it's not a race car. Make sure your air filter is clean.

Also, the mechanic that sold you a "tune up" on the zd30, may have just ripped you off. The fuel pump is ECU controlled, so no serviceable parts there, the boost is preset by the waste gate, so no adjustments there. At most all they did was your regular service (fuel, air and oil filters) and clean you MAP sensor and clean the air flow sensor, and charge you extra for the convenience.

first thing to do is check if the trip computer is recording accurately. if you change the tires it will alter the km's it reads which throws the fuel consumption readings out.

a chip will give extra power. i doubt you will get economy improvement as the timing is fairly good and most chips on these alter fuel only.
it can cause an increase in fuel usage, the more fuel you pour in the more power you get and the more power you have the more you tend to use it.

if its your misses daily drive, what i would do is go load it up and then take it for a blast. go tow the boat etc. you will probably find that it will run a whole lot better after woulds.

What air filter you using? When was it changed last?

I have a 2003...Steel tray,3" exhaust,16" wheels and always have 500kg's on the back...My light comes on at 480k's as well...When I tow the camper with the canopy on the back and loaded up with gear I get about 350k's before the light comes on...I have had the truck since new and it has always been the same...
As with all the vehicles I have had,everybody seems to get better fuel economy...

Cheers...Sparra

Sparra said:

I have a 2003...Steel tray,3" exhaust,16" wheels and always have 500kg's on the back...My light comes on at 480k's as well...When I tow the camper with the canopy on the back and loaded up with gear I get about 350k's before the light comes on...I have had the truck since new and it has always been the same...
As with all the vehicles I have had,everybody seems to get better fuel economy...

Cheers...Sparra

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That last comment may well be the main factor. Take the brick off your right foot?

hey guys, thanks for all the input.

nakedape, i just replaced the air filter two tanks ago, with a genuine nissan item.

yeah good point robmacca, next time i fill up i'll note the l's put in and the k's i get.

When i say he tuned it, im relating to the tunit chip. he wound the setting back from 9, running rich, to 7 which he said was the best balance.

Hey sparra, grass is always greener hey?

Also, my tyres are 265/75/16 not 265/65/16...

I would disconnect the chip from the ECU and see what happens.
The chip might be faulty and feed the engine too much fuel.

tony d22 said:

I would disconnect the chip from the ECU and see what happens.
The chip might be faulty and feed the engine too much fuel.

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or the engine isn't getting enough air (snorkel/80series airbox/egr) nor getting the exhaust out quick enough big dump pie/larger exhaust) and that's contributing to the overfuelling?

tony d22 said:

I would disconnect the chip from the ECU and see what happens.
The chip might be faulty and feed the engine too much fuel.

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How do i disconnect it? is it just a plug in thing or wired in? I've had nothing to do with these things...

The other thing is with the bigger tyres your speedo could be out, I know its not a huge difference but if my speedo reads 470km the gps (i now rely on )could be around the 500km mark on mine. While its not huge it still makes the economy that little bit better

My 2005 3Ltr gets to 630km before the light comes on and i drive it like i stole it.

After putting on the tunit chip economy got better, around 10-10.5ltr per 100km.

My power and economy is always better in the dry season than in the wet even thought its always 32 in Darwin.

Rumpig said:

My 2005 3Ltr gets to 630km before the light comes on and i drive it like i stole it.

After putting on the tunit chip economy got better, around 10-10.5ltr per 100km.

My power and economy is always better in the dry season than in the wet even thought its always 32 in Darwin.

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yeah that sounds more like it! What size tyres u running and what setting is ur chip on? Sounds like u have a great set up there mate...

I get 700 km per 70L in mine, 750 if I drive carefully... But that's a 2.5L so probably not a fair comparison

chvrl-8 said:

yeah that sounds more like it! What size tyres u running and what setting is ur chip on? Sounds like u have a great set up there mate...

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265/75 next size up from factory. Cost me some power down low but 2.5 "exhaust from flex join back got that back. Chips on 9 but i had it reprogrammed to suit the other mods i've done.

When my fuel light came on at 630km it took 68 ltrs to fill when the tank takes 75 ltrs. If i was only geting 480 ks a tank i'd be pissed off, something must be wrong.

Thanks rumpig. It looks like i have some investigating to do. Thanks to everyone for the input.