John_H schrieb am 19.12.2006 22:59:

I know this facts. Therefore I look for another method. It must go, how
one sees at ScanGauge http://www.scangauge.com/

Do you think the same amount of fuel is needed to keep the engine at
2500 RPM in neutral as when climbing a hill at 2500 RPM, or driving on
a highway in the highest gear at 2500 RPM?

Don't you notice that you have to press the pedal differently in these
situations?

Are you stupid???

No.

No.

That depends on the load and the "throttle" position, among other things.

Mike Romain wrote in message
458C126C.606C47C0@sympatico.ca:

I've found that my car gives remarkably consistent fuel consumption
figures - as long as I drive in the same way - not varying by more than +/-
2 mpg from one tankful to the next. Some of that variation may be due to not
always filling up to the same point on successive tankfuls - different pumps
cut out at different levels in the filler pipe. Out of sympathy for cyclists
and motorbikes, I don't fill up so full that I can see the fuel in the pipe,
because spilled diesel is *slippy*. (I did once drove behind a car that was
gushing fuel from its filler cap on every left turn. The driver seemed
utterly indifferent when I flashed him and pointed out that spilled diesel -
if it was diesel rather than petrol - is a skidding hazard, that spilled
petrol is a fire hazard and that anyway he was wasting fuel, which is not to
be recommended at inflated UK prices.)

(All these figures are miles per UK gallon: multiply by 4/5 to get miles per
US gallon)

40 mpg    stop-start driving in heavy traffic: maximum 30 mpg but with
frequent stops and starts from rest or crawling forward in traffic jams

45 mpg    local journeys - max 15 miles, many T junctions, roundabouts
(traffic circles, rotaries) and traffic lights

52 mpg    long motorway journeys (fairly constant 60-80 mph)

58 mpg    long journeys around 50-60 mpg with few junctions or stops

My car (Peugeot 306 HDi) has averaged 50 mpg over its severn-year,
104,000-mile life so far. And thankfully the consumption shows no sign of
getting worse with age - once it levelled out ofter the car was run-in, it's
been remarkably constant since then.

Is the thread suggesting that there is no easy way of calculating
instantaneous fuel consumption with a diesel-engined car? Or is it that you
need to measure the rate at which diesel fuel is being consumed, rather than
inferring it from other parameters like engine revs, speed, gear? Because
I've driven plenty of diesel cars (eg VW Golf, Citroen C5) which have a
second-by-second display of fuel consumption and can also average this over
a journey.