[Jancko995]

Hello, I was rely wondering wth is with this car... I have 2011 i30 1,6 90PS .. And I'm sure today that 6th gear is completly usless in terms of MPG/economy,..

I feel like it has a lot of resistence when in 6th gear, the fuel consuption is like +0.5L/100km  minumum!. Like when driving downhill the fuel consuption doen't lower,,... it's still at 4l/100 . (1.5L/100km  in 5th gear)

Drove in 5th today on highway at 110km/h and i had like 4.6,5L ... If I  had in 6th, I would get 5.6, 6L/100km ..


So if anybody does know what's wrong, I would be grateful..

[mjt57]

Mine seems to work fine in 6th.

Oh, can you please translate those figures? I'm not sure what the commas are supposed to mean. Sorry.

[Phil №❶]

, = . 

[Phil №❶]

Probably need a bit more info to help.

The nature of the terrain plays an important part in the fuel calculation. If I remember correctly, the fuel economy is actually calculated by comparing information, distance traveled in pulses, to the fixed measure of fuel supplied to the motor, interpreted as a pulse. This is how the "instantaneous" fuel consumption is derived in the GD model. Total distance compared to total fuel pulses are used in the FD model, providing only an overall average. It is possible, if on a gentle incline at the wrong speed, to use more fuel in 6th than 5th, due to the torque curve, efficiency and power output of the engine. There is also atmospheric pressure and temperature of the air to consider as well.

[Dazzler]

.. and the trip computer may not always give a true picture for short periods of driving.

[Asterix]

Well, the highway from Koper to Ljubljana is very flat the first few kilometers but then there's some very hefty inclines  (they are at least when towing the caravan)

Jancko, my next door neighbour have a i30 just like yours. He says when doing 110 on the highway, on the flat roads, he can get around 4,9 L/100 km

[elantraelite]

would the depowered 90ps change anything?

[Jancko995]

I fixed some mistakes      ..australian people- the less liters per kilometer the less fuel you use..

No, no, I'm a fuel eficenty "master", and I tell you when I swich to 6th gear, the motors feels a resistent than in other gears. The fuel consuption to the power's producing is not correct.

I watch my actual fuel consuption, are u saying that that thing is not correct at all?

And I know about the terain(incline,decline) I'm aware of that...  I'm generaly talking about flat highways

Phil what do you mean, with GD and FD?

Wel I think my i30 cw  doen't get 4.9L/100km   in 6th at 110km/h

[Phil №❶]

The FD is the previous model i30. On this model, the fuel consumption shown IS ONLY THE AVERAGE FOR THE WHOLE TANK.

On the current model, the GD, there is a display of instantaneous fuel consumption and or average fuel consumption, similar to the FD. I don't own this model, but I have briefly seen it on my mate's GD Premium.

The instantaneous display shows what is happening immediately, not what has happened since you last refueled and can vary considerably from very low to very high depending on what the engine is required to do. Unless you continue to do whatever it reports, it only slightly affects the fuel tank average.

Hope I explained it ok.

[PhireSideZA]

Could it maybe be something like a binding or sticking brake pad that is killing your fuel consumption?

[Johnno]

I did a fuel economy / efficiency course with Volvo trucks when I was driver/trainer with a combined weight of 38 tons and i would think the same principles would apply to cars to a certain extent.  The course we did was from Trafford Park to Blackburn via A666 / A675 thru Belmont  village about 30 odd miles. I know its not a long distance but the average mpg of the semi on the flat is 6.5 to 7.5 mpg and this terrain is mostly up hill as some of you from the UK may know. What we found with some of the drivers that as soon as the engine revs drops slightly they were knocking it down a gear and were over revving thus using more fuel when the truck would pull just as good at lower revs in a higher gear.

Maybe what you are sensing when you say 'resistance ' is that the engine is labouring and you think something is holding it back

To cut a long story short is to keep it in the power band. The 90ps power band starts at 1500 to 2750rpm  as long as you keep it in that range in 6th gear you should in theory achieve the figures. Anything under or over is waisting fuel

i slip mine into 5th when going up a slight hill
leave 6th for the flat and down slopes...

[Johnno]

heres a quick comparison sheet

[Jancko995]

Maybe what you are sensing when you say 'resistance ' is that the engine is labouring and you think something is holding it back


To cut a long story short is to keep it in the power band. The 90ps power band starts at 1500 to 2750rpm  as long as you keep it in that range in 6th gear you should in theory achieve the figures. Anything under or over is waisting fuel

I feel/see it on "current consuption" meter,..
    I think Hyundai did something strange, maybe they didn't optimize the computer for the 6th gear.. 

And yeah,.. I have the 1st i30 not the 2013 new- current model.
And i30 I - wich was then facelifted in 2011

[Phil №❶]

Unless your speed is slow, that's petrol engine thinking, Drew. Not really necessary with your Diesel. Ours are auto's and we live in hilly terrain with freeway. The Diesel stays in top gear on the hills but my 3.8lt petrol on the same road drops back a cog on inclines. Different gearing of course, but I can feel more power available in the i30 than the 6 cyl Holden Commodore.

Once your Diesel has loosened up, I think you'll be pleasantly surprised.

[Just Rick]

jackno995, simple answer is the trip computer in the FD's are a piece of crap and rarely work correctly,once my trip computer goes above 6ltr/100,it will never fall below unless I reset the computer,I have had Hyundai look at it numerous times and they say it is working within parameters,so basically you have a trip computer like mine,a shitty one,work your fuel consumption out manually and I think you'll find your getting better consumption than you think.

I was reading somewhere on here last night about how someone was getting over a thousand Kilometres a tank but every time they filled up their trip computer only says they have a range of 790 Kilometres,this is like mine I get 1000 plus Kilometres per tank but each  time I check the trip computer after filling,it tells me I only have a range of 840 K's