[Aussie Keith]

Diesel fuel economy Frequently Asked Questions.


What are the manufacturers stated fuel consumption figures?

                                        Manual    Auto

Combined (L/100km)          4.5        5.6    
Urban (L/100km)                5.9        7.5    
Extra (L/100km)                 3.7        4.5
CO2 (Combined) g/km       119       147    

Fuel tank capacity (Litres)    50 (AU 2013 GD hatch specs)

* Source: Australian Design Rule 81/02. Fuel consumption will vary depending on a combination of driving habits and the condition of the vehicle.

http://www.hyundai.com.au/vehicles/i30/specification-range


How are these figures calculated?

The urban (city) cycle takes 195 seconds. It's performed four times. It comprises 36.9 percent of the total distance; the extra urban (highway) cycle, which takes 400 seconds, is performed once. It comprises 63.1 percent of the distance.

The single fuel consumption figure, displayed on the label, is determined by applying these distance percentages to the actual urban and extra urban consumption numbers, and adding the two for a final average.

The fact that 63.1 percent of the average is derived from the highway part of the test explains why the figure on the fuel consumption label bears little relationship to how much fuel your car will use in the city. It also explains why the gap between reality and laboratory numbers escalates in proportion to the size of the car and the capacity of its engine.

The NISE2 study test devised by the Transport Systems Centre of South Australia is also a laboratory test, but it is based on an analysis of actual driving patterns in Australian cities, using Global Positioning System (GPS) tracking of routes, speeds and traffic flows.

It's called the Australian petrol composite urban emissions drive cycle, or Petrol CUEDC. The test is a simulated 19.442 kilometre course, and takes 29.95 minutes. Four types of conditions are simulated: residential, congested, arterial and freeway. CUEDCs were also developed for each of the major diesel powered vehicle categories.

http://www.comlaw.gov.au/Series/F2005L04084
http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2012:138:0001:0077:en:PDF (Annex7)
http://transportpolicy.net/index.php?title=Australia:_Light-duty:_Diesel_CUEDC


Why am I not matching these figures?

In theory you could if you matched the conditions of these synthetic tests exactly. Since however you are driving on real roads with variable traffic conditions and changing weather, its unlikely you will meet them. Condition of the vehicle including tire pressures may also be factors as will individual driving style. It has been reported that fuel consumption of new engines improves around the 10000km mark.


What can I expect then?

It depends on road and traffic conditions, your driving style and whether you have an auto or a manual. The auto will use slightly more fuel on average. Figures around 5.5l/100km or better have been routinely reported for highway driving with the automatic transmission. Around town, 7.5l/100km have been reported although some people report better figures than this and some worse. Hard acceleration hard or idling for long periods will have an adverse effect on fuel consumption figures.


My trip computer says that I'm using more than this. Why?

This shows average fuel consumption based on the current flow rate of the fuel to your engine which in turn is determined by load at any time. It can be a good indicator of how much fuel your car is using right now. When the average is reset it starts recalculating average fuel consumption and gradually comes down as you drive. This may then take some time to reflect actual average consumption, especially if you do mostly around town driving.


Is there a better way to check?

Carefully filling the tank to the top of the neck of the filler and measuring the distance between fills is the most accurate measure of fuel consumption.

http://motormouth.com.au/myvehicle/consumptioncalculator.aspx


Quick guide to fuel consumption

Range based on 45 litres consumed.

900km driven  = 5 l/100km = 56.5 mpg
850km driven  = 5.29 l/100km = 53.4 mpg
800km driven  = 5.63m l/100km = 50.17 mpg
750km driven  = 6 l/100km = 47.08 mpg
700km driven  = 6.43 l/100km = 43.93 mpg

Note: manufacturer states fuel tank holds 50l (AU) 53l (UK).


I'm not getting close to those numbers. What could the problem be?

Post a question in the forum and we will take a look.

[Shambles]

A useful FAQ - thanks


Just a couple of things...

Fuel tank capacity (Litres)    50 (2013 GD hatch specs)

I thought it was 53L ?



Could you add headings to the numerical columns?

Combined (L/100km)        4.5    5.6   
Urban (L/100km)              5.9    7.5   
Extra (L/100km)               3.7    4.5
CO2 (Combined) g/km     119    147   

[Dazzler]

Steve it appears the GD may only be 50 Ltrs by what some owners are saying (Not 53 Ltrs as per the FD)

[Shambles]

I'll chase this up with Hy later - we need to be certain

Steve it appears the GD may only be 50 Ltrs by what some owners are saying (Not 53 Ltrs as per the FD)

I've got at an i30 brochure in my hands and it states that the Fuel tank capacity is 53 litres.  And it's for the GD by the way.

[Dazzler]

In the GD manual of which I have a PDF copy it says 50 Litres?? and on the Hyundai Australia website it says 50 Litres too!

http://www.hyundai.com.au/MultiMediaFiles/Cars/i30/pdf/Hyundai_new_i30_Specifications.pdf

That's kind of odd Dazzler.  Wonder what is going on.  Conflicting information.  Sort of irrelevant really as I know I can get way more than 53 litres into the FD - think it was way over 60 litres, as Hans Tholstrup reported. 

Will have to wait and see what the situation is with the new GD when it arrives.

[Dazzler]

That's kind of odd Dazzler.  Wonder what is going on.  Conflicting information.  Sort of irrelevant really as I know I can get way more than 53 litres into the FD - think it was way over 60 litres, as Hans Tholstrup reported. 

Will have to wait and see what the situation is with the new GD when it arrives.

Yes very odd, as I thought someone had mentioned a brochure with 50 Litres on it too 

Some GD owners have already got well over 53 litres in the GD as well 

[Shambles]

Well I thought it important to get it right. If there's a discrepancy in the printed material or even a region-specific physical variance, a FAQ needs to incorporate this

Especially if that FAQ is to make it to our portal page

[Dazzler]

Very true Steve.. For now it should be modified to read "Fuel Tank Capacity = "Somewhere between 50 and 53 litres but don't be surprised if you get 60 litres in there" How does that sound? 

[Phil №❶]

There in lies the problem.

Tank size could vary between countries.

No DPF's in Diesel in Oz, so the L/100 will vary too.

I can see a C.O.W. here

[AlanHo]

We had a discussion about this on the forum a couple of months ago. Evidence suggests that the torsion beam rear suspension on Australian and USA cars compared with the multi link in Europe accounts for the difference.

UK GD is 53 litres

Aus GD is 50 litres.

[Doggie 1]

Early information and brochures in Australia listed the fuel tank capacity as 53 litres in the GD.

Somewhere along the way they have changed their minds and all literature now refers to 50 litre capacity.

In my previous FD (53 litre) tank I frequently put in 60+ litres.

In the new GD (50 litre) tank, the most I've got in is 54 litres so far.

[rustynutz]

We had a discussion about this on the forum a couple of months ago. Evidence suggests that the torsion beam rear suspension on Australian and USA cars compared with the multi link in Europe accounts for the difference.

I don't think we ever found any proof that that was indeed the case......
Btw, I've sent off an email to Hyundai Australia asking that very question so hopefully they get back to me...

[Aussie Keith]

Its possible that not all pumps are accurate despite being subject to monitoring and calibration. I have stuck more fuel into a tank than it could physically hold once and never went there again. Nor was my question as to how you can put more fuel into the tank than it actually holds ever answered.

As for the FAQ itself I've hacked together a shell, lets modify it in whatever way to get it right. Information sources per the references other than the AU Hyundai website for the fuel figures.

http://www.hyundai.com.au/vehicles/i30/specification-range

UK capacity is indeed 53 litres:

http://www.hyundai.co.uk/new-cars/i30 - weights and capacities

I've also based my range calcs on 45 litres, not a full tank. Going a full tank between fills if for pros. Plus there's always a chance in older cars of picking up something undesirable out of the bottom of the tank, water traps and filters notwithstanding.

.. Plus there's always a chance in older cars of picking up something undesirable out of the bottom of the tank, water traps and filters notwithstanding.

I would have assumed the pickup is from the bottom anyway.

[Aussie Keith]

.. Plus there's always a chance in older cars of picking up something undesirable out of the bottom of the tank, water traps and filters notwithstanding.

I would have assumed the pickup is from the bottom anyway.

Good point. Is this conventional wisdom out of date then in the age of fuel injection?

[komaterpillar]

.. Plus there's always a chance in older cars of picking up something undesirable out of the bottom of the tank, water traps and filters notwithstanding.

I would have assumed the pickup is from the bottom anyway.

Good point. Is this conventional wisdom out of date then in the age of fuel injection?

why would fuel injection make a difference? pickups are almost always at the bottom, always have been and probably always will be.

[Aussie Keith]

.. Plus there's always a chance in older cars of picking up something undesirable out of the bottom of the tank, water traps and filters notwithstanding.

I would have assumed the pickup is from the bottom anyway.

Good point. Is this conventional wisdom out of date then in the age of fuel injection?

why would fuel injection make a difference? pickups are almost always at the bottom, always have been and probably always will be.

I'm thinking of old petrol engined vehicles where rust, water and other debris was screened out by a small Ryco filter and where small particles could clog a carburetor jet no problems. In working on Italian cars over the years I've seen plenty of Weber and Dellorto carbs that have had corrosion in the float bowls from accumulation of water owing to ineffective filtration. There was always sediment in the float bowls indicating inefficient filtration and leading to clogged jets and poor performance. 

Now with fuel injection there is more sophisticated fuel filtration. And therefore I wonder if the ancient wisdom of picking up debris from the bottom of the tank when running on empty is still an issue in either petrol or diesel engines. I'm suggesting the superior filtration on fuel injected cars in particular compared to earlier more basic filtration arrangements makes this less of an issue than in the past. And with diesel engines typically having multi stage filtration, was it ever an issue in the first place?

[Phil №❶]

Filtration is probably sorted, but water in diesel is still disaster. I'd like to see the I30 with a visual filter and drainage valve.

[komaterpillar]

.. Plus there's always a chance in older cars of picking up something undesirable out of the bottom of the tank, water traps and filters notwithstanding.

I would have assumed the pickup is from the bottom anyway.

Good point. Is this conventional wisdom out of date then in the age of fuel injection?

why would fuel injection make a difference? pickups are almost always at the bottom, always have been and probably always will be.

I'm thinking of old petrol engined vehicles where rust, water and other debris was screened out by a small Ryco filter and where small particles could clog a carburetor jet no problems. In working on Italian cars over the years I've seen plenty of Weber and Dellorto carbs that have had corrosion in the float bowls from accumulation of water owing to ineffective filtration. There was always sediment in the float bowls indicating inefficient filtration and leading to clogged jets and poor performance. 

Now with fuel injection there is more sophisticated fuel filtration. And therefore I wonder if the ancient wisdom of picking up debris from the bottom of the tank when running on empty is still an issue in either petrol or diesel engines. I'm suggesting the superior filtration on fuel injected cars in particular compared to earlier more basic filtration arrangements makes this less of an issue than in the past. And with diesel engines typically having multi stage filtration, was it ever an issue in the first place?

Water is still an issue no matter how good the filters or water traps. See this thread:
https://www.i30ownersclub.com/forum/index.php?topic=15786.msg173126#msg173126
And my point about the pick up being on the bottom was, regardless of fuel level it will still pick up sediment and water from the bottom

[Aussie Keith]

Therefore, the old adage still holds true. Good explanation, thanks.

[rustynutz]

Btw, I've sent off an email to Hyundai Australia asking that very question so hopefully they get back to me...

Still waiting.....

[Hornet]

It is said in previous posts "Water in diesel fuel" or something like that. So Hyundai should allow us to use Chem Tec Diesel Additive. This product somehow deals with reasonable amounts of water (condensation), kills the diesel fungi and improves consumption. Hyundai Dealer says it is not an approved additive and will void warranty if used. Shame but read this

https://www.i30ownersclub.com/forum/index.php?topic=22085.0

[Tourer_Guy]

Regarding the fuel tank size question, it seems the GD hatch is 50 litres, but the GD tourer is 53 litres.

[Doggie 1]

Could be.
I know the GD hatch is 50l and the FD hatch was 53l.

[Tourer_Guy]

The Hyundai website also lists the hatch fuel capacity as 50l and the tourer 53:

i30 Tourer Specifications and Range - Hyundai Motor Company Australia - Hyundai

[Doggie 1]

I think it's in relation to the rear suspension design of each.

[Tourer_Guy]

Makes sense.  I've heard this elsewhere as well.

[noels_hobby]

Latest Data from 2010 I30 fd 5 speed manual
fuel economy data last fill 17/05/2018 2010 fd I30 tyre pressure 40 psi oil shell helix ultra ect c3 5w-30 fuel ult diesel BP bruce HWY north pump 4 odo 207597 trip 267.7 ltrs used 14.19 weight 12.412 calculated max distance 55 lrt 1038.760 km/ ltr 18.88653982 ltr / 100km 5.294776119 price 154.9 docket 21.98 use combine