Fuel consumption.

[Dave]

Filled mine up about 2 days ago and got a average of 10.4L/100km's.

 

[Tills]

Have done about 13500 in the ST auto now and after a ecu reset it has started to give me beter ecconomy last tank 75% highway with some hills it returned 10.1/100 getting happier.

 

[Arty_74]

Hmm.... Since I changed tyres from stock 255/70/16 Dunlop AT20 to 265/75/16 Mickey Thompson MTZ I have gone from 700k to orange light to 580k!
Nothing else has changed so I am a bit miffed the tyres made that much difference.
Not that I would change them back :grin:

Will report again after next tank.

Murph

Murph, I believe you should be adding 5% to your km's travelled each tank due to your bigger tyres, comparing your odometer reading with std tyres with larger tyres the vehicle is actually travelling 5% further than what is currently showing. e.g 580km + 5% = 609km (as a comparison to the std gear)
Am I right guys?

 

[Scubamurph]

Hmm..... I was only going off the odo reading. Will do a comparison of odo vs gps on my next long drive. odo could be out as you say.

Cheers Murph

 

[Arty_74]

Your speedo would have definately changed, but I did read somewhere on this forum that the speedo and odometer measure from different sources? again is this correct guys?

 

[Scubamurph]

Yeah speedo has changed. It is almost spot on now. Maybe 1 kph out at 100.

 

[Old.Tony]

Forget the speedo for a moment.

The ECU of the car knows - on factory tyres - both precisely how far it has travelled and how fast it is travelling. Just ask one of the guys with standard tyres and a ScanGauge to compare their ScanGauge speed reading with their GPS - it'll be VERY close. The speedo needle is moved to position by a voltage passed to it - and it'll only ever be close, never exact.

With larger wheels, you need fewer revolutions of those wheels to cover the same distance, so the car's odometer will show less km than actually travelled.

265/70 R16s have a 2% larger circumference than standard. 265/75 R16s are 5% larger. So your 580km should more accurately be 609km.

That's still a loss, and there's a good reason for that. Your diff ratio is still the same, and the engine/gearbox/diff/wheels were all arranged for the power available. Larger wheels represent (in physics terms) a longer lever (distance from axle centre to road surface). This means it takes more effort to turn the wheels = higher fuel consumption.

 

[mojo]

Excuse my ignorance, but i thought the analogy would be more like - taking away first gear and instead adding 6th gear. So that starting would be difficult on clutch, like starting from second gear, once you start moving it should all be the same. I thought the advantages are once on the highway you are able to cruise at 110km and at the same time economy would be great.
(eg The only reason I can see why the Hilux gets better economy is that it has a higher 5th gear, when compared to D22. They seem to have the same figures in city driving, yet the Toyota gets 7.1 on highway)

Forget the speedo for a moment.
Larger wheels represent (in physics terms) a longer lever (distance from axle centre to road surface). This means it takes more effort to turn the wheels = higher fuel consumption.

 

[Old.Tony]

Excuse my ignorance, but i thought the analogy would be more like - taking away first gear and instead adding 6th gear. So that starting would be difficult on clutch, like starting from second gear, once you start moving it should all be the same. I thought the advantages are once on the highway you are able to cruise at 110km and at the same time economy would be great.
(eg The only reason I can see why the Hilux gets better economy is that it has a higher 5th gear, when compared to D22. They seem to have the same figures in city driving, yet the Toyota gets 7.1 on highway)

There is that aspect as well, absolutely. That's the point in relation to how much force is required, and how much extra fuel is needed.

But electronically speaking, the computer in the Navara knows that in order to travel one kilometre, the wheel has to turn over 416.96 times. If you put 265/70 tyres on (like I have), the wheel only has to turn over 409.45 times for the same distance, but the Navara's computer thinks that you've only travelled 409.45 * 2.39829 = 981.9798405 metres.

If you put 265/75s on, the wheels only have to turn 395.96 times, and the Navara's computer will assume that you've only travelled 395.96 * 2.39829 = 949.6269084 metres.

That's purely an issue with the computer. It is programmed with a wheel circumference of 2398.29mm and 265/70s have a wheel circumference of 2442.27mm, with 265/75s having a circumference of 2525.53mm. In order to get the odometer accurate, you'd have to reprogram the wheel size. Maybe Nissan can actually do that - I don't know.

Oh, that Jaycar box would be useless here. The ECU uses an aggregate figure from all 4 wheels' ABS sensors to calculate the number of wheel rotations (and therefore the distance and speed). There's a sensor on the gearbox to count the revolutions of the output shaft, but I think that might only be used for checking the info. The manual's fairly specific about the info being taken from the ABS sensors individually, and aggregated to provide a best-fit average - which is probably a "best of 3", allowing it to accommodate for wheelspins or lockups.

I gotta hand it to them in a way. It beats the shit out of the old cable-in-the-bearing-cap like my old (old) Volkswagen had.

 

[mojo]

I think I might go for the bigger tyres, eventually. Mainly for fuel economy because I do a lot of highway driving.
Speaking of VW's, I was reading about the new Amorok. When in top gear at 100km/h, the amorok engine revs at 1800rpm. My d22 is close to 3000rpm's at 100km/h. No wonder the vw has economy of a small car.
I don't really mind odometer is off, it will probably even itself out, mine is currently 10km off when i am doing 100km/h according to my gps.

 

[KraftyPg]

At 100 my Nav only revs at 2000RPM so given the two year difference between the Anorak and my Nav I consider that fairly reasonable. I'd imagine under similar conditions the 140KW Nav would have closer to 1800 RPM at 100 than it would to my 2000RPM too and the 140KW Nav is still more go than and Bettle ute.

 

[ggfc04]

D22 STR 2003
ZD30 T/D
Manual
weight : stock + toolbox
65L for 700km's
thats about 70% Highway 30% around Town/Bush.. i change gears at 3k rpm and tryes are 31's at about 40psi and no additives

 

[Converted]

Model : D22 STR 2011
Engine : 2.5
Auto or Manual : Manual
Rough guess on weight 200kg over standard
8.6L/100 around town ( mainly freeways monash eastlink etc with a little main roads)

I drive easy thou never rev over 2600 rpm cruise on about 90 on the freeway.
i had a au S2 XR8 ute which use to get 660 out of a tank around town 800 on the highway.

 

[Dave]

Last tank I averaged 10.14L per 100km's.

That major service helped.

 

[Element-RB]

Model: D22 STR 2006
Engine: ZD30DDT
Klms: 89000
Auto or Manual: Manual
Rough guess on weight : 2000kg

On stock Diesle 9.89L per 100Klms
On Vortex Diesle 9.71L per 100Klms

IMO the Vortex stuff feels more responcive.

 

[Dave]

Mine is averaging 10.47L/100km's on the last tank.

I use the loud pedal alot though.

 

[KraftyPg]

Lots of loud pedal saves listening to the rattles and bangs of the engine does it?

 

[Dave]

Na I mean't as in breaking 100km/h.

You must get about 7L/100km's in the D40 by going no more then 70km/h. Lol.

 

[KraftyPg]

Whoa there speed racer I only do 70 on the highway, every where else its 35.

 

[Dave]

Here come's speed racer.

How fast you had the 40 Krafty ?

I reckon they'd do 180km/h atleast.