Real World D4 fuel consumption

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Originally Posted by discotwinturbo

We travelled 210 kms each way on a highway run last weekend to Capel and back for an ODE.

Indicated was 16.5....actual was 18.9.

Our trailer is a triple axle angle load weighing in at 3.5 tonne.

Brett....

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Thanks for that Brett, the weird thing was I seemed to get better economy in the Hills along the Hume. I recon I was fitting a side wind at the time as well which doesn't help. You wouldn't kow what a 200 would get with the same weight??

Ian

Without going into lots of detail I travel around 120 to 140 kms per working day most of which is at highway speeds. Like most here my speedo or should it be 'rough speed indicator' is not that accurate with 116km/h (110km/h speed zone) eliciting nil response from the constabulary, not even a glance my way?

So given that level of error mentioned above you can take what you want from the L per 100km readout on my trip computer. Anyhow according to the D4 trip computer I averaged 10.3L per 100km over my latest longer trip (478km). This was with just the vehicle (2011 D4 HSE) my wife and myself and some light luggage travelling at around 118 km/h indicated speed. Yes I did pass the police mobile speed traps on this trip and no they did not stop me?

Given this (computed?) level of economy is way better than some of my previous vehicles I wont worry about a computer upgrade or chip unless I become concerned about power.

That said the 3.0L engine has more than enough grunt!:cool:

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Originally Posted by flotty1974

I've just come across to Sydney from Adelaide while towing a 2 horse angle load and loaded to the hilt with stuff for the Sydney Royal. Coming across the Hay plains I ended up having the dash tell me that I was getting 18lt. So here are my two questions. Is this what some people with big vans and other large floats are getting or are they getting better? and secondly, is there someone in Sydney near Blacktown that I can have my ecu hooked up to run a quick check before i head back across the plains? Cheers in advance.

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Ian, you could try Davis Performance Landies at Annangrove - about 20 mins form Blacktown:

Land Rover, Range Rover, Discovery + all vehicle make and models service and repairs

Or Trivett at Parramatta:

Trivett - Authorised Servicing & Repair Centres

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Originally Posted by Weird Al

Graeme.

Ha I hate this sort of thing....it would be so much easier to explain verbally with many hand gestures.:)

Perhaps it was the bad spelling, but in my example the speedo does read faster,

"That is when you spoeedo says 100kmh you are doing 95"

Oh yes and pardon my ignorance but whats a CCF and a CC (cruise control?)


TerryO

No what I meant was....in standard form with standard tyres in my D4 when travelling for an hour at an indicated 100kmh.

The speedometer will be reading low and I will actually be travelling at a speed closer to 95kmh but the odometer will be correct and I will have covered 100km.

In the A.C.T. they have odometer marker posts on the side of the highway for 5km, when I drive past and set the tip to zero at the zero mark, by the time I get to the 5km mark my trip meter is out by less than 20m. So 20m out of 5000m is 0.4%, much more accurate than the speedometer which says 100kmh when my GPS says 95kmh.

So if I were to change to larger tyres the speedo would become more accurate but in turn the odo would read less, as I don't know that it can auto correct for that sort of thing. What I mean is just an intentional offset between the odo and speedo from the factory. Clear as mud eh...:(

Redback

"Our 2.7l D4 won't do anything under 1600rpm in 4th, 5th or 6th."

You're a little harsh on the old D4. Now having started my driving career in V8's im used to plenty of grunt from 1000rpm, I will admit that even for a diesel the 2.7 does not have much 'grunt' bellow 1600rpm. However whilst no rocket ship my D4 seems happy enough to motor along most arterial roads at 80kmh at 1350rpm without labouring.

But yes much below that it "won't do anything.":angel:

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I dont understand this. The odometer is based on tyre rotations - it is calibrated at the factor for x inch tyre wheel combination on that vehicle. The computer knows if a 30 inch say (whatever stock is) rotates once that is 1.1 metres or whatever and it works out distance from that - simple. If a larger tyre is added later to the same rim the computer doesnt know that...so the speedo will be underreading and so will the odometer. If the tyre has a 10% greater rolling distance for one revolution than stock then the odometer will be showing 10% less k's travelled than were actually travelled and will show 90kph when the vehicle is actually travelling at 100kph.

Good fuel figures in this thread.

Cheers

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Originally Posted by ozscott

I dont understand this. The odometer is based on tyre rotations - it is calibrated at the factor for x inch tyre wheel combination on that vehicle. The computer knows if a 30 inch say (whatever stock is) rotates once that is 1.1 metres or whatever and it works out distance from that - simple. If a larger tyre is added later to the same rim the computer doesnt know that...so the speedo will be underreading and so will the odometer. If the tyre has a 10% greater rolling distance for one revolution than stock then the odometer will be showing 10% less k's travelled than were actually travelled and will show 90kph when the vehicle is actually travelling at 100kph.

Good fuel figures in this thread.

Cheers

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In these cars there are two different algorithms; the speedometer reading and odometer readings are calculated differently, from different reference figures. This is so the car can be programmed for various markets where there might be a legislative requirement for the speedo to be optimistic by different % figures, but the odometer still needs to be accurate.

Certain diagnostic tools can alter the inputs to the two algorithms, thereby accounting for different tyre sizes.

Cheers,

Gordon

Thanks Gordon - I suppose the point I was making is that it cannot auto correct but rather needs calibration by a human with a computer. Any change in tyre size must affect speed and distance readings and display and therefore if changing tyres and wanting accuracy some computer programming is required. Nice feature to have available though.

Cheers

The worst I have seen in my 2010 3l D4 was on a trip we did From Perth to Ceduna and back over the Australia Day weekend.

We averaged 16.5 l/100km (688 l for 4165 km) and the worst section was 18.2 l/100km from Perth to Norseman via the Hyden to Norseman gravel track. On this section all that we had causing extra drag was a Kimberley Mycube roof top tent but we had a head wind and were cruising at about 125 on the GPS with the cruise control on.

On the return trip we were towing a 1300 kg Adventure Camper Trailer (picked it up in Ceduna), still with the roof top tent as well, but travelling at around 107 on the GPS with the cruise control on and we were getting around 17 l/100km all the way from Ceduna to Perth.

Obviously speed makes a big difference to the D4 fuel consumption, especially with the increased drag of a roof rack or roof top tent. I don't usually get as bad as 18 l/100km, even towing our 1800 kg caravan, which we usually tow at just over 100 kph actual speed.

Re speedo accuracy, my odo is spot on and the speedo reads 5kph over at any speed. Hence, I assume it is set for 0% and plus 5kph by Landrover.


Bob

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Originally Posted by flotty1974

Thanks for that Brett, the weird thing was I seemed to get better economy in the Hills along the Hume. I recon I was fitting a side wind at the time as well which doesn't help. You wouldn't kow what a 200 would get with the same weight??

Ian

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I do know about the 200 fuel economy. There a number of them at events with floats, but not quite has heavy as our trailer. When I last spoke to an owner I was using the Touareg to tow, and this for the same trip in the Touareg was 16.5 lp100....Better then the Disco. This cruiser owner was blown away....he was doing over 20 lp100 and he had the same amount of highway cruising. Neighbour has a 200 and towing their 2.8 tonne float sits just over 21 lp100. So I gather at 3.5 tonne it would be a little more?

Brett....

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Originally Posted by BobD

Re speedo accuracy, my odo is spot on and the speedo reads 5kph over at any speed. Hence, I assume it is set for 0% and plus 5kph by Landrover.

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The original CCF setting is 3.5% + 2 kph. The other option is 2% + 0 kph.

Is there any way to set things up to get an accurate fuel consumption? Surely the engine management system knows exactly how much fuel it's spraying into the cylinders, so should be able to give a very accurate consumption based on that and the accurate odometer reading.