Thread: D3 Trip computer & Avg fuel consumption

Originally Posted by morcha

Hi all.

Can anyone tell me how the trip computer in the D3 calculates average fuel consumption?

Cheers.

Not 100% sure, but from my understanding it makes its calcs from the following inputs

Revs
Speed
History (memory on km's travelled)
The gear you are travelling in
Fuel used/left

There must be some very accurate fuel flow rate measurement, because (on my 03 RR anyway) it works out L/100Km almost instantly, which you couldn't get from just those ^^ inputs.

Modern trip computers usually take the flow rate measurement from the adding of the duration of each injector opening event.
If the computer knows the pressure and the time open, it knows the fuel used.
Regards Philip A

It checks lot's of stuff!

Even so, most of us have found it's around 0.5-1.0 litres/100km below actual consumption.

I better be more careful when I'm bragging to my mates with Pajeros and Territories about my fuel consumption then!

The trip computer showed 8.9L/100 for my last tank of fuel. Even if it is 9.5 in reality, that is still damn good for a big Rangie (obviously a diesel....).

Originally Posted by Jamo

It checks lot's of stuff!

Even so, most of us have found it's around 0.5-1.0 litres/100km below actual consumption.

F a r k ! I'm in trouble then. As I type, my average (admittedly town k's with no long runs at all) is 14.6l/100Km!!!!! If you're right Jamo, it is actually worse than that. Bugger!

Away,

You're fuel consumption isn't good for a TDV6. Even in Melbourne with lots of traffic I get around 12 lt/100km.

You must be a lead foot or you have a heck of a lot of stop start traffic in Geraldton

Maybe you are towing your camper.

Chris

You've all got me wondering now!

The 2nd day I had the D3 I went for a 100% HWY drive of 180km and returned 10.4l/100km according the trip meter, which I found astounding and unbelievable. This week in city driving its floating around the 16s which I'm not unhappy about.

What prompted my question was that the value shown moves around more quickly than what I expected, leaving me thinking that it calcs on a short time/km cycle, which would mean its fairly useless I would have thought.

I'll compare it actual when I fill up again.

Cheers.