Average fuel consumption computer reset

[Kjl001]

Hi All

I have a 2005 X5 3D ltr sport, my question is that my average fuel consumption always reads optimistic when checked against my manual calc by approx 5 mpg. I have reset it after a refil but it still reads high.

Is there any constants or factors used in this calc that can be adjusted via any secret menus ????????

[JCL]

With a diesel, inaccurate OBC fuel consumption readings suggest that the engine may have had an aftermarket chip installed. Considering that the vehicle is new to you, are you aware of any engine modifications? If so, removing them may correct the fuel consumption indication.

[Kjl001]

As far as I am aware the car is standard, the previous owner had made no changes to the chip.

many thanks

kev

[bigwave2255]

same experience for me.

my 2005 3.0d auto indicates 7.9 litres per 100.

but in reality is doing 8.8 litres per 100.

also has anyone noticed that the speedo when indicating 100 kmph is really doing 95 kmph (GPS)

although the trip meter seems to be fairly accurate (stock diameter tyres)

Ewen

[Fraser]

My 2005 3.0d's OBC fuel consumption is pretty much spot on with the manually calculated figure. Mind you, filling a diesel to exactly to the same spot each time is difficult as the diesel fuel foams up so much so you have to be really patient to get it right.

With regards the speedo reading fast, this is common for most cars. In my experience Toyota speedos are amongst the more accurate while Alfas are amongst the worst. I presume car manufacturers do this so as to avoid problems with speeding fines were you think you are actually going slower than you are.