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ebajema



Member Since: 24 Mar 2011
Location: Lagos, Nigeria
Posts: 298

Accuracy of the fuel consumption measurement

Who has done the comparison between the fuel consumption measurement of the FFRR itself (shown on the screen) and actually looking at miles and liters/gallons put into the tank ??? Can they please let me know what the differences are ??

Over here I don't fuel the car myself (our driver does that) and I get quite a substantial difference in fuel consumption between the pump liters and FFRR measurement (30%). I would like to find out if that sounds "reasonable" although I am afraid the answer will be no and we have to find out where we are being scr**ed.

Also does anyone know how the fuel consumption is actually measured ??? Just out of interest. 2006 Range Rover Supercharged, Zambezi silver, black laquer/jet interior and all options.
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!

Post #90946 8th Nov 2011 10:07am
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bozmandb9



Member Since: 06 Dec 2010
Location: Wallingford, Oxfordshire
Posts: 846

On my S/C I like to think that the computer is highly accurate, however it seems to have been programmed by Alastair Campbell, and realises that the driver might not really want the whole truth, so applies a little spin to dress up the news in a more palatable form. So it shows an average overall for my car of 16.5 mpg, where the reality is probably around 13 (I'm running on LPG).

I'd say even when i run purely on petrol it makes little difference to the optimism of the LR redacted official data! :roll laugh:

Edit, as to how it's calculated, I believe it's SOP for Alastair's optimistic scenario, take the reality, add 30%. Simples! 2006 Supercharged

Post #90950 8th Nov 2011 10:35am
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stan



Member Since: 13 Jul 2010
Location: a moderate moderated moderator moderating moderately in moderation
Posts: 8158

England 2005 Range Rover Td6 HSE Auto Cairns Blue

mine is accurate , some members readouts are not...do what i did , a tank to tank fill up and calculate the consumption to see if it corresponds with the readout, but it needs to be over a long journey so that the readout gives you a true figure..... ..............................




this is handy Wink

Post #90964 8th Nov 2011 11:01am
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DavidP



Member Since: 20 Oct 2010
Location: Keerbergen
Posts: 178

Belgium 2006 Range Rover Td6 Vogue Auto Bonatti Grey

may be it's being syphoned out and sold down at badagry. Alternatively is it doubling up as a taxi?

Post #90972 8th Nov 2011 11:27am
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ebajema



Member Since: 24 Mar 2011
Location: Lagos, Nigeria
Posts: 298

Hi David, the taxi trip would still show the kilometers, also I am the only one driving the car unless it is used for getting fuel. As for the syphoning, it is supposed to be quite hard to do on the FFRR but I think it is possible. Again not a lot of time to do it as he takes the car and brings it back straight away after fueling.

I suspect the pumps here are not "calibrated correctly" to be honest....... 2006 Range Rover Supercharged, Zambezi silver, black laquer/jet interior and all options.
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!

Post #90973 8th Nov 2011 11:33am
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bozmandb9



Member Since: 06 Dec 2010
Location: Wallingford, Oxfordshire
Posts: 846

I think it's more down to the accuracy of the consumption figures on the S/C. As I said above, I've always found them highly optimistic both on my current and previous S/C! 2006 Supercharged

Post #90987 8th Nov 2011 12:01pm
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Emperor Mong



Member Since: 07 Jul 2010
Location: London
Posts: 387

United Kingdom 2010 Range Rover 4.4 V8 Autobiography Auto Baltic Blue

I think it is optimistic. I've never done the calcs myself but a simple test is to zero the trip when it is brim full and then look at the expected range.

First point is that I normally get a number that is a little over 400 miles. I have achieved that only once in 4 years of ownership. Normally a tank gets me 350-380 miles before I feel I need to fill it - suggesting that the calculation (which I assumes uses the recent mpg to work out range) must be optimistic by about 10%.

Secondly, keep an eye on the two numbers. The sum of those two generally grows a little (I've seen it almost get to 500 miles on a long run). Suggests more optimism.

Finally, look at the numbers when it's half empty - you'll see something like 180 miles covered, 210 miles range - clearly the second half of the tank won't get you further than the first half.

None of this is scientific but I have no doubt that the mpg is a bit generous.

Post #91000 8th Nov 2011 1:23pm
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JustinP



Member Since: 24 Oct 2010
Location: Cambridge
Posts: 783

United Kingdom 2006 Range Rover Supercharged Vogue SE Auto Java Black

I've compared the average mpg of my 2096 SC against the number of litres to brim my tank over a couple of months, and the value reported by the car was generally within 0.2 mpg, so I would say this figure is very accurate.

The distance to empty on the other hand is useless, it always starts high, then drops off steeply when the tank drops below 1/4 of a tank. 

Post #91012 8th Nov 2011 2:42pm
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Paulo



Member Since: 28 Sep 2010
Location: Glasgow
Posts: 165

Scotland 

If you have an I-phone, I've been using an APP called "Road-Trip" for the last year or so....

I type in odometer reading, litres pumped, cost per litre wtc. and it records all MPG data.

I can also record any additional expenses etc. and breaks down expenses on a daily basis....

I find my cars Fuel reading to be within 0.4 MPG from using this APP, but my car isn't a RR..... Laughing

It does make sobering reading though.....

£4006.81 in Petrol since 1st Jan 2011 or £13.18 per day averaging 15.09 MPG..... You don't want to know the total costs.... Big Cry

Post #91017 8th Nov 2011 3:53pm
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Mikeyjd



Member Since: 14 Jun 2011
Location: Wrexham
Posts: 347

Wales 2003 Range Rover Td6 SE Auto Zambezi Silver

I did a longish test a while back. I ran over 1000 miles, the computer showed aprox 26.5mpg and my actual tank filling calculations showed aprox 25.5, so not too bad I guess. Td6 SE
................................

Previous LR- Disco 300TDi Auto

Post #91019 8th Nov 2011 4:00pm
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