Technical MPG consumption / sensor?

[martbass]

Hi
I had my 2004 elx jtd for a couple of weeks now and Just about used to it....I really like it.
I wanted to ask if anyone knows how the mpg consumption reading works?

1. Is there a sensor of sorts which physically guages the ACTUAL amount of diesel used?

2. Or does it just give a reading based on preset values set around the kind of speed you are doing ? (if that makes sense!)

I have been driving it with a very light foot for around a 30 mile trip at around the 60 mph mark and it generally reads 36-38mpg on the consumption reading.
Surely at this speed / driving style I should expect at least 40-50mpg?

If there is a sensor, could it be faulty?
if not, what could cause such a poor reading?

The engine seems to respond fairly quickly to accelerate and seems to run well.

Not sure if this is relevent, but I got my boot stuck on the throttle, (completely floored) and the revs (thruming loudly!!!) MAXED out at 5000rpm.
Almost as if being 'held back'

My Brava petrol would whack into the red if floored.

thanks in advance

 

[TinyUK]

The fuel computer gives a reading based on the average since the trip was last reset not instantaneously as you drive (unfortunately).

They are notoriously unreliable and there is a school of thought that they read in US gallons. I personally just think they are rubbish!

If i work my consumption out from fill to fill i get roughly 40-42mpg with mostly short journeys and as I like to maximise on sleep and get up as late as possible for my 5.30am starts I tend to be in a rush.
According to the computer however I average around 32mpg.

 

[TinyUK]

Hi

Not sure if this is relevent, but I got my boot stuck on the throttle, (completely floored) and the revs (thruming loudly!!!) MAXED out at 5000rpm.
Almost as if being 'held back'

My Brava petrol would whack into the red if floored.

thanks in advance

Just noticed the last part of your post, is this your first diesel?
Although i am unable to give precise figures on a multipla, typical diesels give their peak torque at between 1800-2200 revs, they dont rev anywhere near as high as a petrol. At 5k there would be nothing left to give bar the piston rings!