Thread: Fuel Consumption for D4 with Trailer

Tombie, would not air trapped in vehicle tank use less fuel for the fill up, resulting in improved fuel consumption figures (less fuel for same kM).
Regardless of such variables that may be thrown into the equations after some 22 consecutive refuelling stops and data many errors are minimised and certainly not resulting in a understandable average 17% error.
Volume change relative to temperature very minor. A further comment of wheel size was previously raised, which I disregard as it is the same wheel diameter, same driving manner etc used for both the vehicle and real life calcs using bowser litres.
I have previously set up a MoTeC engine management system which provided a fuel consumption readout. This was based on injector flow rate, # of injectors, fuel pressure and on time of the injectors. This was with accurate to < 1%.
I can only conclude LR make a conscientious effort to make fuel consumption figures look good, to the extent of 15-20%.

Yeah my Audi was near spot on. The disco is just shy of 17% off.

But I think we could start a new thread, if one hasn't already been started, where people post their results. But all have to follow the same routine and fill to the brim. Can't trust pumps.

Originally Posted by Tombie

Are you aware you can adjust the trim for fuel consumption with the GAP IID tool?

G'day Mike, I don't have the Gap tool yet, but could just enlighten me on what the "trim" is please (?).

In concern with getting figures from fills etc, I reckon I'd have a hard time with this. Would have been easy to do before I had the Aux tank installed, but now I seem to get lots of air pockets, and as such, I'm not sure this would work for me like this, not to mention, at some servo's, the car is on a lean.
Is there, or are there, any other ways to try and work this out, other tools etc.

In the CCF there is a value usually set at 7% for fuel reading.
Changing this to -5.5% or there about brings it to within 0.2l/100km.

The problem with air in the tank or foaming is you just don't know which tank full had it...the previous tank or the current tank...

The only true way to measure accurately is to run the vehicle dry. Fill from known fuel containers, drive until it runs dry and calculate.

A good guesstimate would be to run the vehicle to the light, put 20 litres in and then do it again...

My calculations were done using my Lease App for 4 years, where the odometer was entered with every fill... after 4 years I was out by about 2% which I wasn't concerned about.

One thing I'm convinced of is that Avg consumption is over a unit of time, not a tank of fuel....

On the consistent run from Whyalla to Adelaide 395km I get a consistent 9.7l/100km @ 114km/h SOG (once remapped and modified exhaust) - previously it was 10.9/100km.

With the crossover on the back it's 14.5/100km at 114km/h.

114km/h according to the gauge or GPS?

Originally Posted by Tombie

In the CCF there is a value usually set at 7% for fuel reading.
Changing this to -5.5% or there about brings it to within 0.2l/100km.

I don't get it. Why would it be set to a value that is going to be wrong from factory and not correct until changed?

Originally Posted by Redback

OK so all these stories I hear of getting 10s, 11,and 12s are just that, stories, only time I got 12l/100ks was when the camper was empty and the D4 was empty on a trip to Gosford and back and it was high 12s.

It's great to be towing at 12 to 13s again, like we were getting in the D2, and having the longrange tank it's great to have that extra range.

Can only speak for myself Baz. Filling at each bowser with same routine and then calculating against distance driven from last bowser. Odometer might be a poofteenth out.

Vehicle only (3,000 - 3,100kg) plus roof rack and spare tyre on top at 110 kph was almost down to 12 neat.

Originally Posted by catch-22

I don't get it. Why would it be set to a value that is going to be wrong from factory and not correct until changed?

Make you belive you are getting good economy
The olde Volksywagen cheating,who would have thought?????

All sensors need calibrating,I guess at the factory they just put it to something the owner would like.

When I was a sodbusters slave,I calibrated the boomspray every time I changed chemical brews,different viscousity fluids etc,I don't know why I cared so much back then,they didn't care when I injured my back.I was like a broken tractor,no good to anybody
Andrew