I’m averaging >33mpg doing mostly m-way under 70mph. This is calculated and not the trip readout ( which is pretty accurate once setup properly). These are expensive cars to run in many ways but not fuel economy. 2012 TDV8 Vogue (L322)

JayGee Post #64702031st Oct 2022 10:25pm

Quote:

This is calculated and not the trip readout ( which is pretty accurate once setup properly).

Could you share how one does this?
Is it via a special menu I was reading about?
If so, is it possible to do on the 4.4 TDV8.
 2012 4.4TDV8
2000 Honda S2000

mine: overall average --> 20mpg
best on highway long trip 80mph --> 24mpg

anyhoo, compared to the yearly price of maintenance on a FFRR, fuel consumption is a joke  "it needs some intelligence to undestand you may not have enough"

@spitfireS - adjust the CCF value for mpg offset and tyre sizes ( if you are not running a stock size) using the GAP IID tool. 2012 TDV8 Vogue (L322)

Today I doing a consumption test on mine L322 4,4TDV8.
Test conditions: highway (couple of small villages on the way), almost no traffic, fixed speed 100km/h, no wind, no rain, AC off, engine and transmission warm (its very imortant, with cold transmission it drink a lot). Car without DPF, so no burning process during test drive.
Refueling before and after test full tank.
Result:
Distance 133km.
Average speed 89km/h
Computer average fuel consumption 7,0l/100km
Refueling after trip 11l.
Real average fuel consumption 8,27l/100km
Factory claimed fuel consumption 8,2l/100km
So, everything looks correct, except computer shown value. 7,0 only??? How its possible? Its ridiculous!

For years now, I've noticed when a car comes back from a dealer service it "appears" to be doing better MPG on the trip computer than before. I've long suspected some dealers adjust the trip computer's compensating factor.

On the later L322's there is a percentage offset stored either in the instrument cluster or the CCF (can't remeber off the top of my head, but someone above has suggested it's in the CCF).

A while ago, I came across this value while using my GAP IID tool. It was set at +8% and wildly opptomistic, saying the car was doing much better MPG (or L/Km) than it actually was by using the tank brimming method. So I adjusted it to be 0% - Now it reads just about spot on.

My TDV8 4.4 was doing terrible MPG recently, turned out to be a binding rear brake caliper!

Jon 1992 RR Classic 3.9 efi Vogue
===================
Both my fatties now gone...
Previous: 2011 L322 4.4 TDV8 Vogue SE /// 2002 L322 4.4 V8 HSE /// 2009 Discovery 3 2.7 TDV6 XS /// 2004 Defender 90 TD5 /// 1993 110 V8 Snatch Landrover /// 2005 Discovery 3 2.7 TDV6 SE (Aus) /// 1990 110 Isuzu 3.9 County (Aus) /// 1976 Series III Trayback (Aus)

CCF - IPC instrument Pack - Trip fuel Eco adjust 2012 TDV8 Vogue (L322)

I have observed the REAL Fuel Consumption of my 4.4TDV8 since I bought it in January 2020 (so almost 3 years now). I have done it with all of my cars, because it is a good way to monitor your car's health and maintenance intervals (I always do maintenance by engine running time not kms driven).

So I have answers for most of the questions asked here in this thread.

Like you can see in the chart below, indeed the car computer always shows better mileage than actual and it varies a lot also.
Here's the explanation and it is all logical and adds up, so don't you guys rush to change your calibrations in CCF just yet.

The difference is caused by computers inability to count for infinite consumption per distance, while car is stationary. While stationary with engine running, the computer counts it as 99,9l/100km, but actually it is infinite and this is impossible to calculate with.
It also draws out beautifully in summertime and wintertime difference, as you can see, in winter the computer seems to lie a lot more. That's because in winter my car does a lot more stationary running, that computer does not account for, concerning fuel per distance. Yes, the computer also doesn't account for the fuel burned by the FBH, which is used also in cold times, but last winter mine didn't even work, but that's another story (yet to be solved).
So the difference between the real and the computer's consumption depends on how much time you are spending while idling stationary and how much are you using FBH.
So for my example if I would correct my fuel consumption calibration in CCF in the summer, it would be off again in the winter and vice versa.

So if you want to know, if your computer's consumption reading is off, you need to do this:
1. Fill the tank to the top at the gas station by the highway.
2. As soon as you drive off the station and enter the highway, reset trip computer.
3. Drive at least 200kms on the highway NONSTOP! very important.
4. Pull to the gas station by the highway and stall the engine right away.
5. Fill the tank again to the top.
6. Compare consumptions, they should read the same.

I have tested this several times and my consumption is spot-on, no need for calibration.
That way, I even disproved my own suspicion, that the computer does not account precisely for additional fuel consumed while DPF Regeneration. It does.

Best real consumption I have managed to get with this car, is 6,7l/100km. It was on one of those tests so computer showed the same. It was a ca 250km trip on pretty flat landscape and cruising at 96km/h, only few overtakings and as few brakings as possible.

So that's that.
I might of forgotten something so fire away if you have some questions.

Click image to enlarge

Your test results could be viewed that at constant cruising the formula is about right.

I'm with Webbie, over 30 mpg on a motorway under 30 mpg around town.

Fill up once a fortnight

Everything is approximate  Geoff

that's about what I get as well Geoff

Yep, around 40mpg on highway and around 25mpg in town.

I hope no one minds if I revive this old thread but I’m actually quite proud to record my best ever MPG after a round trip to Inverness from Portsmouth. Mostly cruising @~65 MPH on the motorway with some A roads and around the lanes driving whilst in the highlands. Two adults + luggage & 1 chubby dog !

Click image to enlarge

My trip display average usually shows around 25 and i hardly ever reset it , little bit of town driving but usually used for longer slogs up to Scotland either full of luggage and a bike n 2 dogs (+wife) at around 80 or tugging a tone and half of tin tent up to north yorkshire , if i remember to reset when in Scotland at beginning of a forntnight away it usually shows high 20's to low 30's before the drive home as a lot less traffic so plenty of steady 50/60 A and B road driving . I'm happy with that as you can't expect comfort and pace to be free .

I've been tracking mine brim to brim over the last seven months (24K miles) doing a mix of 80% slogging up and down the A1 from East Anglia to the north east and 20% round the doors.

Over that time pretty much every tank averages 31mpg calculated/33-34mpg on the OBC. 2012 (L322) 4.4TDV8 Vogue SE, RSE, Fuji White over Arabica.
Previous V8s: BMW 645Ci, P38 4.6, P38 4.0, Merc CL500
Previous others: Honda x1, Volvo x7, Rover x6, BMW x6, Ford x1, Mercedes x2, Skoda x3, VW x2, Renault x2, Citroen x1, Mazda x3, Nissan x1, Audi x3, Kia x1, Fiat x4, Subaru x3, Austin x2, Triumph x2, Jeep x2, Hyundai x2, Lexus x1, Mitsubishi x1, Saab x2... and some others I've forgotten!