Instantaneous Fuel Usage Readout Figures

[AllanJC Lurker Find all posts View Profile Close AllanJC]

Hi Folks,

I changed the fuel filter on my V6 yesterday and everything seemd OK. The car idles and drives nice and smooth - I think the plug change on Sunday helped the most here though.
But this morning while driving to work, I noticed that the instantaneous fuel usage readout was showing crazy consumption figures that jumped around all over the shop. Even idling at the lights it would go upto 99litres/100km or sometimes show 0litres/100km :?: .
Does anyone have any clues as to what might cause this? Do I need to reset something?
Any suggestions appreciated.

Cheers,
Al

[damonat Advanced Member Find all posts View Profile Close damonat]

Re: Instantaneous Fuel Usage Readout Figures

what device are you using to get these figures?

[AllanJC Lurker Find all posts View Profile Close AllanJC]

Re: Instantaneous Fuel Usage Readout Figures

what device are you using to get these figures?

Hi damonat,

Just the on board trip computer readout which is set to the instantaneous readout mode.

Cheers,
Al

[timmay5.7 Advanced Member Find all posts View Profile Close timmay5.7]

Re: Instantaneous Fuel Usage Readout Figures

my old car did that... in relation to how heavy my foot was on the pedal
99l/100kms for flat foot,
0/100 for if i was coasting with no gas.

[AllanJC Lurker Find all posts View Profile Close AllanJC]

Re: Instantaneous Fuel Usage Readout Figures

my old car did that... in relation to how heavy my foot was on the pedal
99l/100kms for flat foot,
0/100 for if i was coasting with no gas.

HaHAHa :mrgreen:
Only trouble for me at the moment is the computer is telling me I'm using 99l/100kms while i'm idling at the lights :shock:

Cheers,
Al

[Guest Close Guest]

Re: Instantaneous Fuel Usage Readout Figures

Al,

A reading of 99L/100km is fine when stopped at the lights because you are going nowhere. i.e. you are using a bit of fuel yet distance covered is 0km. When you do the calculation, any number divided by zero is infinity, hence 99L/100km because that is the only way the trip computer can display infinity. Other cars display L/hour when the car is idling - which is a more appropriate figure when idling because L/100km is not valid at those times.

[AllanJC Lurker Find all posts View Profile Close AllanJC]

Re: Instantaneous Fuel Usage Readout Figures

Hi amts,

Thanks for the reply.
What you says does make sense. I was actually waiting for the readout to change to a l/hr reading when stationary like the commodores do. Sounds like the Prado can't do that
I don't know if it is my imagination here or not, but since changing the fuel filter, the fuel usage readout seems to jump around more now than before. Even when holding a steady speed on flat road. :?: :?: :?:

Cheers,
Al

[Way2go Member Find all posts View Profile Close Way2go]

Re: Instantaneous Fuel Usage Readout Figures

I can confirm my t/c definitely reads 99L/100km as well when idling at the lights.

Steady speed on a flat road - is the cruise control on? Even if you think your foot is steady you'll probably find that it isn't and the road probably isn't exactly flat either.

My consumption does jump around a bit as well, unless the reading is jumping in the 10s of litres per 100km without any real change in accelerator pressure/gear down change/etc., I would be too worried about it.

[AllanJC Lurker Find all posts View Profile Close AllanJC]

Re: Instantaneous Fuel Usage Readout Figures

Way2go,

No cruise control on this morning on the way to work.
The fluctuations seemed to be in the 10s of litres this morning (but I could be wrong), will check it out again on the way home this arvo.

Cheers,
Al

[AllanJC Lurker Find all posts View Profile Close AllanJC]

Re: Instantaneous Fuel Usage Readout Figures

I monitored the fuel usage readout figures on the way to work this morning and it seems the variations I noted yesterday may have indeed been related to changing road conditions and not the instrumention - ops:
Thanks for the feedback folks.
Thats why this forum is so valuable -

[Guest Close Guest]

Re: Instantaneous Fuel Usage Readout Figures

It's called the placebo effect. When you 've done something good for your 'baby' you think that it has changed its performance. Like when I change the engine oil, I feel that the engine runs smoother and goes faster, but in reality, there is probably no noticeable change.