i30 Owners Club

FUEL ISSUES & ECONOMY => DIESEL => Topic started by: plasticphyte on November 18, 2019, 07:28:49

Title: i30 GD (2013MY) Premium 1.6 - Fuel consumption increasing while idle
Post by: plasticphyte on November 18, 2019, 07:28:49
Hi all, thought I'd pick the brains trust to see if anyone else has experienced something similar, etc.

I've got a 1.6 CRDi i30 Premium GD from 2012 (MY2013) that has done just over 120200Km in six years (bought new). I typically averaged 5.8L/100K for the first 3-ish years of the vehicles life, but over the last few this has steadily increased. I know this because I've been meticulously recording the fuel logs after each fill, and clearly see the trend over time (see the attached screenshot).

The issue that I'm experiencing is that when idling at traffic lights, I can see the fuel economy ticking up while idle. It's a very noticeable change, as I will stop at lights and see it at 6.0L/100K, then a few seconds later it ticks up to 6.1L/100K, and in some cases by the time the lights have cycled, it's crept up by over 2L/100K from where it was when I stopped.

Some history:

Some of the increase in fuel consumption can be attributed to the route change, however since changing back it has started to drop, however the primary issue I see now is the increasing fuel economy while idle.
Kicking this around with a few other people, they've suggested that the EGR needs a good clean, which it quite likely does seeing as it's never been cleaned by myself (and not during services as far as I know).

The car has never gone into limp home mode over the time I've owned it (touchwood it won't).
I did raise this at the 105,000K service, but it was kind of ignored/brushed off with a basic "fuel economy changes due to so many variables". This service wasn't done at my usual service centre.


(https://i.ibb.co/WKNktZ0/Fuel-Stats.jpg) (https://ibb.co/kcV41jJ)
Title: Re: i30 GD (2013MY) Premium 1.6 - Fuel consumption increasing while idle
Post by: tw2005 on November 18, 2019, 07:54:24
Hi all, thought I'd pick the brains trust to see if anyone else has experienced something similar, etc.

I've got a 1.6 CRDi i30 Premium GD from 2012 (MY2013) that has done just over 120200Km in six years (bought new). I typically averaged 5.8L/100K for the first 3-ish years of the vehicles life, but over the last few this has steadily increased. I know this because I've been meticulously recording the fuel logs after each fill, and clearly see the trend over time (see the attached screenshot).

The issue that I'm experiencing is that when idling at traffic lights, I can see the fuel economy ticking up while idle. It's a very noticeable change, as I will stop at lights and see it at 6.0L/100K, then a few seconds later it ticks up to 6.1L/100K, and in some cases by the time the lights have cycled, it's crept up by over 2L/100K from where it was when I stopped.

Some history:
  • The vehicle has been serviced regularly to each service requirement.
  • The original tyres were changed over to Adrenaline R03's at the ~77,000K mark.
  • The tyres have just been changed over to Dunlop Sport's at the 119900K mark.
  • My route to work & home did change around the time my average fuel consumption has started increasing, however it has changed back to what it was (this route change occurred as a result of quite a lot of roadworks on my normal route).
  • My typically commute is home to work and back again, with little deviation, and consists of roughtly a 90/10 split of highway/urban driving.
  • Aside from the route change, my driving style hasn't changed (not hard on acceleration, but not a Slow Susan either)
  • The fuel tank did have a fairly horrid build up of algae on the fuel sock (pre-filter/whatever its called) which has been cleaned out (I was silly and didn't put anti-bug treatment in the tank every few tank fills).
  • Injection system cleaned at last service (120,000K).

Some of the increase in fuel consumption can be attributed to the route change, however since changing back it has started to drop, however the primary issue I see now is the increasing fuel economy while idle.
Kicking this around with a few other people, they've suggested that the EGR needs a good clean, which it quite likely does seeing as it's never been cleaned by myself (and not during services as far as I know).

The car has never gone into limp home mode over the time I've owned it (touchwood it won't).
I did raise this at the 105,000K service, but it was kind of ignored/brushed off with a basic "fuel economy changes due to so many variables". This service wasn't done at my usual service centre.


(https://i.ibb.co/WKNktZ0/Fuel-Stats.jpg) (https://ibb.co/kcV41jJ)
The figure increases because it's consuming fuel whilst stationary. It's also an average figure. The wife's FD CW sits at 5.9 av . One thing I notice on my i40 is it automatically resets the fuel average on a fill. Does this happen on the GD i30 too? With the FD it does not unless you choose to so it's av is actually over an extended period of time.

My NF sonata also resets on refills. have you done any manual calculations to compare to like fill the tank to the brim , do the Ks then refill then calculate?
Title: Re: i30 GD (2013MY) Premium 1.6 - Fuel consumption increasing while idle
Post by: plasticphyte on November 18, 2019, 08:43:55
Yes, the fuel economy resets automatically on each fill. I should have mentioned that the increasing fuel economy statistics have never increased the way that I'm seeing them increase currently. In fact, I've never really seen them increase that dramatically. To be more specific, I can be at a set of lights for ~1-2min and see it increase 2-3L/100K, that hardly seems realistic given it's ticking over at fairly low idle. The economy calculation drops while driving back to a more realistic figure that I'd expect given the several years I've had running the vehicle.

On the whole, I'm not so worried about the long term fuel consumption trend upwards, as it's started to come back down in the last while (per graph), my primary query is really more about what seems to be unrealistic fuel consumption while idling.
Title: Re: i30 GD (2013MY) Premium 1.6 - Fuel consumption increasing while idle
Post by: tw2005 on November 18, 2019, 09:46:23
"I can be at a set of lights for ~1-2min and see it increase 2-3L/100K"

Is this shortly after a fill and the average has been reset?
Title: Re: i30 GD (2013MY) Premium 1.6 - Fuel consumption increasing while idle
Post by: AndreaACME on January 27, 2020, 16:55:37
Might be a a dynamic regen,  they often start in unexpected moments and the user is not alerted unless it is a forced regen (clogged DPF).
Title: Re: i30 GD (2013MY) Premium 1.6 - Fuel consumption increasing while idle
Post by: CraigB on January 27, 2020, 18:08:02
Might be a a dynamic regen,  they often start in unexpected moments and the user is not alerted unless it is a forced regen (clogged DPF).
This could be possible if Australian GD i30’s had a DPF...which they don’t  :)
Title: Re: i30 GD (2013MY) Premium 1.6 - Fuel consumption increasing while idle
Post by: nzenigma on January 27, 2020, 22:00:53
The figure increases because it's consuming fuel whilst stationary. It's also an average figure. The wife's FD CW sits at 5.9 av . One thing I notice on my i40 is it automatically resets the fuel average on a fill. Does this happen on the GD i30 too? With the FD it does not unless you choose to so it's av is actually over an extended period of time.

My NF sonata also resets on refills. have you done any manual calculations to compare to like fill the tank to the brim , do the Ks then refill then calculate?

Same conclusion here. Wife is asking about the changes with her GD crdi.

@plasticphyte  If  you get your diesel from a high turn over station there should be no need put anti bug additive in your fuel. I did do a clean out , the owner got fuel from a BP servo on the Ippi-Gatten highway. The business was closing down so it was dregs or slow sales.
If you are suspicious then a double strength dose of Moli antibug will fix it.

You will find your Facebook  :rolleyes: 'experts on everything' ratting on about EGR. The inefficiency mainly comes from the tar deposits being left in the inlet manifold. Go to a reliable mechanic and get that area cleaned during the next service.
Title: Re: i30 GD (2013MY) Premium 1.6 - Fuel consumption increasing while idle
Post by: ideal09 on January 30, 2020, 21:45:55
In i30 GD settings menu you can choose if you want the computer to reset the avg consumption at every fill.
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