i30 Owners Club

FUEL ISSUES & ECONOMY => DIESEL => Topic started by: peon2t on September 20, 2012, 20:40:09

Title: Average consumption suddenly doubled
Post by: peon2t on September 20, 2012, 20:40:09
Hey

Today I had a strange issue with my new i30 (which I have driven about 200km so far).

The average consumption according to the trip computer was 5.5 l/100km so far. From one second to the next it went up to more than 10 l and lowered again to about 7 l during the next some hunderd meters. Then I parked the car, so I can't say if it would have went back to 5.5 when driving a bit longer, but I image it would be this way.

Of course it's absolutely impossible that this "information" is true because the average consumption of about 200km certainly can't double from one second to the next (at least not as long as there is no leak in the tank).

Now my theory is that this error could have been caused by the fact that I drove up a hill when it happened. So maybe the fuel gauge has been confused by the movement of the fuel in the tank and fancied that suddenly some litre of diesel have disappeared.

Could this be possible? Had anyone a similar experience?

(Tough this would mean that the average consumption is calculated by the fuel gauge and not by the real amount of injected fuel what of course would be quite inaccurate anyway...)
Title: Re: Average consumption suddenly doubled
Post by: Phil №❶ on September 20, 2012, 22:58:33
If this hasn't ever happened to you before, I'd say that there is something wrong somewhere. When you fill up at the fuel station & reset your computer, the fuel gauge does seem to know how much fuel has been put in the tank so it is used for calculating distance to empty but only for that function. It should not be involved for any other purpose, because, as you said it is not accurate enough.

All I can suggest is watch and wait, see if there is any pattern to its behaviour.  :neutral:
Title: Re: Average consumption suddenly doubled
Post by: Dazzler on September 21, 2012, 01:04:56
Sounds like DPF regeneration may have kicked in very early (maybe)  :undecided:
Title: Re: Average consumption suddenly doubled
Post by: neoto on September 21, 2012, 06:36:51
Sounds like DPF regeneration may have kicked in very early (maybe)  :undecided:

Even if this is true, it would not increase it that much...
Title: Re: Average consumption suddenly doubled
Post by: peon2t on September 21, 2012, 09:56:14
@ 847563

I guess I have to wait then - maybe it sorts itself out or it happens again.


@ Dazzler

Like neoto said: Even the DPF regeneration couldn't increase the average consumption over 200km that much. This huge increase would literally only be possible if several litres of fuel would have instantly disappeared.
Title: Re: Average consumption suddenly doubled
Post by: peon2t on September 22, 2012, 16:21:28
I have a new theory. Toady I drove again and noticed, that the average consumption value was changing very quickly. So my new theory is, that whatr happened two days ago was the following:

The average consumption display reset itself two days ago for unknown reasons in the middle of the drive. Because I was driving steeply uphill in second gear  at this time, it then suddenly went up to 10 l. Now that I have driven some km in the city (but always stop n' go) it went down to 8 l again. I guess during the next week it will go back to about 5.5.

Still it's strange that the average consumption display reset itself without any reason in the middle of my cruise. (It's configured to "manual reset")
Title: Re: Average consumption suddenly doubled
Post by: Asterix on September 22, 2012, 18:31:48
Hi Peon

I think you might be right about the resetting.

IIRC AlanHo reported that when he got his new i30 he could reset the computer by accident, when holding his hand in a certain position on the steering wheel. He simply hit the contact for resetting the computer.

Title: Re: Average consumption suddenly doubled
Post by: AlanHo on September 22, 2012, 19:17:56
Asterix
You have a good memory and you beat me to it.

What peon2t describes is exactly what happened to me and I posted photos here to show how easy it is to reset the average fuel economy without realising it. I no longer let my right hand wander to the bottom of the steering wheel - I have become a dedicated "Ten to Two" man with my hands on the wheel.

See post No 45 in this thread

https://www.i30ownersclub.com/forum/index.php?topic=15119.msg167316#msg167316 (https://www.i30ownersclub.com/forum/index.php?topic=15119.msg167316#msg167316)
Title: Re: Average consumption suddenly doubled
Post by: peon2t on September 22, 2012, 20:53:45
It must be like this then.

I didn't realize that the avg. consumption can be reset by pressing the button while driving, I tought it has to be done in the settings menu. Otherwise this theory probably would have come earlier to my mind :)
Title: Re: Average consumption suddenly doubled
Post by: Phil №❶ on September 22, 2012, 23:01:08
Asterix
You have a good memory and you beat me to it.

What peon2t describes is exactly what happened to me and I posted photos here to show how easy it is to reset the average fuel economy without realising it. I no longer let my right hand wander to the bottom of the steering wheel - I have become a dedicated "Ten to Two" man with my hands on the wheel.

See post No 45 in this thread

https://www.i30ownersclub.com/forum/index.php?topic=15119.msg167316#msg167316 (https://www.i30ownersclub.com/forum/index.php?topic=15119.msg167316#msg167316)

I remembered straight away on reading this and was going to post too, ninja'd by Asterix Well done  :goodjob2: :goodjob: :lol:
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