First tank of gas in the Diesel

[BrianElloy]

I’ve moved from a 2011 D4V8 to a 2016 TDV6 and boy am I loving the mileage!

Was averaging 300kms to a tank of 95 octane in the V8 averaging 16-17 L/100 .. just refilled the TD at 657kms averaging 8.4L/100

I’m definitely gonna like this!

[djam1]

By the title I assumed you put petrol in your diesel

[101RRS]

I thought you had converted it to LPG fumigation.

[rocket rod]

You certainly will see the difference but don't be fooled by the numbers you're getting off the dash, if that's where they are from. Do the calcs manually to get the real fuel usage. You'll still be pleased though.

[Milton477]

Mine does just shy of 10l/100 km around town which is excellent for such a heavy vehicle.

[Redback]

I’ve moved from a 2011 D4V8 to a 2016 TDV6 and boy am I loving the mileage!

Was averaging 300kms to a tank of 95 octane in the V8 averaging 16-17 L/100 .. just refilled the TD at 657kms averaging 8.4L/100

I’m definitely gonna like this!

Going on 80ltrs used at 657ks that's 12.18L/100ks not 8.4L/100

[LRD414]

Going on 80ltrs used at 657ks that's 12.18L/100ks not 8.4L/100

And it’s nearly impossible to get 80L in at one fill. Typically you get up to 74L maximum after the gauge registers empty and maybe you’ll get 76L if willing to run on an empty gauge for awhile. A few litres are retained in the calculated remainder to avoid running completely empty. The 657km range does sound about right for city driving at an economy of around 11.3L/100km.

Scott

[BrianElloy]

Going on 80ltrs used at 657ks that's 12.18L/100ks not 8.4L/100

Didn’t say I used 80 liters, don’t think anyone can get 80 litres oit of a D4 tank can they? I filled up right st the warning light and it took approx 64L

[Lukeis]

Hm. My 2.7L gets nothing near those numbers around the city.. stay tuned I’m going to have to test it

[BrianElloy]

Hm. My 2.7L gets nothing near those numbers around the city.. stay tuned I’m going to have to test it

I was about 75% highway on that tank

My current tank is pegging about 9.8 because I let my wife drive it [emoji23]

[LRD414]

So part way through a tank this is read from the dash, not calculated ?

[BrianElloy]

correct ... no idea how accurate the dash is... +/- 50% probably :)

[LRD414]

Anywhere from 10 to 20 percent optimistic with most people around 12-15 percent but there is variation. However no one has ever reported the dash as accurate, been lots of threads on it. Your figures align with most people when corrected for that, as mentioned in earlier posts.

Scott

[cjc_td5]

The fuel usage readout on the dash also appears to be a rolling average (don't know over what interval though), not a reading for that particular tankfull or from last reset.

[Lukeis]

So do we believe the odometer then?

[rocket rod]

Nope. I did a trip last year and the odo said 9000km, my gps said 8500.

[cruiseh]

132878

this is my running sheet. real numbers... we are quite happy with this big old truck

[Lukeis]

Wait so if we are saying the fuel consumption is out when going by the cars odometer, and if the odometer is also out then the ‘actual’ fuel consumption will be even worse again?

i filled up and hit reset on the trip meter today but I have no way of tracking my true distance, also I don’t drive many km’s so this could take a while to report back

[loanrangie]

Nope. I did a trip last year and the odo said 9000km, my gps said 8500.
Stock size tyres ?, don't think a GPS would account for climbing/descending etc on different terrain.

[LRD414]

The odometer is accurate with stock diameter wheels and therefore out by whatever percent increase in circumference is subsequently fitted. I have noted the opposite to Rod on long trips, whereby the odometer slightly undercounts actual distance compared to the signed distances to towns because every wheel revolution is actually further than the odometer calculates (265/60/R18 - 255/55/R19). Highway signs aren’t necessarily 100% accurate but over long enough distances and multiple examples the point can be proven.

Scott

[BrianElloy]

The odometer is accurate with stock diameter wheels and therefore out by whatever percent increase in circumference is subsequently fitted. I have noted the opposite to Rod on long trips, whereby the odometer slightly undercounts actual distance compared to the signed distances to towns because every wheel revolution is actually further than the odometer calculates (265/60/R18 - 255/55/R19). Highway signs aren’t necessarily 100% accurate but over long enough distances and multiple examples the point can be proven.

Scott

Scott is this true? Reason I ask is that it’s a known fact that the speedometer is optimistic by 4-6km/h at 100km/h on stock diameter tyres and as time is a constant the variable must be distance

I found that when I had my 265/65R18 K02’s the accuracy between GPS and speedo was almost dead-on

Now that I’m back to 265/60R18 I’m back in the 4-5 km/hr variance again

Ergo if the Speedo’s are optimistic then so must be the ODO (ie reading more than actually covered)

My humble $0.02

[cjc_td5]

Scott is this true? Reason I ask is that it’s a known fact that the speedometer is optimistic by 4-6km/h at 100km/h on stock diameter tyres and as time is a constant the variable must be distance

I found that when I had my 265/65R18 K02’s the accuracy between GPS and speedo was almost dead-on

Now that I’m back to 265/60R18 I’m back in the 4-5 km/hr variance again

Ergo if the Speedo’s are optimistic then so must be the ODO (ie reading more than actually covered)

My humble $0.02
The speedo is not necessarily on the same calibration as the odo. The odo is trying to read true but the speedo applies a fudge factor to this to purposely read high. The factory setting is +3%+2km/h if I recall correctly? You can change it in the CCF.

I understand you can adjust the odo calibration in the CCF also if you change tyre diameter.

Cheers, Chris.

[LRD414]

It’s as Chris says, odometer and speedo are not the same. By law the odometer is required to be accurate and the speedo is required to never read too high. Most manufacturers apply a factor to the speedo readout to ensure compliance. The fuel economy readout being optimistic is an LR oddity. All these things have parameters in the CCF however IIRC correcting the speedo has proven difficult for some reason, there has been posts on it.

Scott

[BrianElloy]

I just learned something!

[rocket rod]

Stock size tyres ?, don't think a GPS would account for climbing/descending etc on different terrain.

Yes you may be right about the tyres as the ones I have now have 40mm greater circumference than standard but that amount is a minimal change. I reckon the only number that you can trust when doing fuel calcs is the litres used as this is from a pump that has to be tested by an authority so you'd hope it's right. Some may doubt this though. Many others here have mentioned that the speedo doesn't read true speed by varying amounts and my own test show me that the distance differs from GPS (yes, slope is not taken into account) so I guess what I'm suggesting is that anything read off the instrument panel is a (rough) guide only.

[Russrobe]

The fuel usage readout on the dash also appears to be a rolling average (don't know over what interval though), not a reading for that particular tankfull or from last reset.Good point I've noticed this. I estimated the interval was around every 100km. Was judging by driving conditions vs. Speedo change though so just guessing really.

Definitely zero correlation between resetting the trip and the provided l/100km consumption read out. Other than they both reset at the same time.

[101RRS]

don't think a GPS would account for climbing/descending etc on different terrain.

It does - it calculates the distance along a flat surface (horizontal distance) but at the same time it also claculates changes in altitude (vertical distance) and then calculates and displays the actual distance travelled (the slope distance) - the reality at each update (4 a second?) it calculates your position in space so automatically calculates actual distance travelled through space and by calculating this it can then display speed. A GPS cannot measure speed directly but works this out (4 times a second) from the positions it has calculated - you will note the delay in GPS speed when decelerating quickly at traffic lights - you will note that when you stop the GPS speed will still show a speed for a couple of seconds then show zero. GPS speed, always lags by a second or so behind your real speed.