Hyundai i20 Blue drive 1.1 diesel - mpg !!

[Bluebox]

Bought new this year (made late 2013) - "Claimed" 88.4 mpg on combined cycle - I expect a 70mpg average. I am 99% convinced there is an inherent (design) problem with the fuel map .... BUT !
Hyundai won't talk to me (dealer does not even know what a fuel map is (quote) .. so don't go there.
I raised a "customer query / complaint" with Hyundai UK , but the general response is a) we don't have any technical customer interface , and b) there are no updates available ... therefore please go away (what they said was : we will log your communication but not respond any more !).
They won't communicate with me , therefore I have no way of explaining what I believe the problem is - you can guess what sort of result that will have towards resolution !

What do I do , where do I go now ?

(Basically the conditions under which I expect the car to perform best (mpg wise) - which is : warm engine , long run - 200 miles + , top gear , flat road , 55mph - right on top torque curve ... is exactly when mpg is at it's worst ... average on the inaccurate trip computer just drops and drops.)
2nd observation : Car is less economical when engine is warm ... sort of linked to first issue , but again , exact opposite of what my engineering mind says should happen.

PS car runs well otherwise , normal temp , etc - Tyre press are correct and a recent "health check" (link to Hyundai PC - showed no faults)

HELP !!!
PPS average mpg to date over 8000 miles is 64mpg ... actual (computer on car approx 80mpg) .. trying as hard as I can !

[Draigflag]

The 88 MPG figure is similar to the claimed figure for my renault Clio DCI. It is pretty hard to get these figures as the tests are performed under lab conditions and the car doesnt even go over 40 MPH. Im still experimenting with mine, only done 2k so far, but im getting similar figures, mid 60's. Last night however, I drove as if fuel was gold dust, I reset the trip meter and after 30 miles I got an average of 90.6 MPG so it's not impossible to get these high figures, but it almost is during every day driving.

I doubt you'll get anywhere with Hyundai, if you read the small print it will say "fuel figures are only an estimate and are performed under lab conditions. They may not reflect real World driving" or somthing similar.

[Bluebox]

Hmm ...... you too have totally missed my point , try reading the epistle again. It is NOT a "I think I should get 88mpg because it's published in the figures" issue.

[Draigflag]

I read it again. The biggest thing that affects fuel consumption is driving style, so I can only assume that your style of driving is the direct cause of not getting as many MPG's as expected. If you click research vehicles and check out people's "real world" figures, you'll probably notice that a good 95% are getting less than expected MPG. There is nothing wrong with your car.

[Draigflag]

Your car is a clone of the Kia Rio, if you look at the other Rio's with the same 3 cylinder engine, they're getting 53 to 57 MPG average, so you're probably getting the right fuel consumption.

[Bluebox]

Originally Posted by Draigflag

I read it again. The biggest thing that affects fuel consumption is driving style, so I can only assume that your style of driving is the direct cause of not getting as many MPG's as expected. If you click research vehicles and check out people's "real world" figures, you'll probably notice that a good 95% are getting less than expected MPG. There is nothing wrong with your car.

Oh dear , you sound like Mr Hyundai.
Let's put it in perspective
a) I also have other cars (lots) - if I can get a regular 53 mpg out of a Fiat Multipla , then I do have the driving ability to get lots of mpg's (I can take car for a 60 mile run (i20) and get indicated 99.9 mpg ... but that is irrelevant)
b) My driving style is good for fuel economy . Nearly all the cars I have owned , I have been 10 to 15% above govt figs with .... know all the tricks about reading the road ahead , avoid braking , etc etc.. got the T shirt
c) As an engineer , it's 100% illogical to get better fuel consumption with a cold (cooler) engine
d) from experience (limited to a few 100,000 miles I admit ... cough) , I would always get better mpg on a long easy run , vs round town driving. Your experience is obviously different.

Hmm ... I think there is something wrong with the fuel mapping on the car , I will get it fixed with or without Mr Hyundai's help
Lets just quietly agree to differ at this point ... rgds.

[Draigflag]

Only trying to help. Good luck, with an attitude like yours you might need it.

[trollbait]

Is the fuel slowly getting worse over time? Perhaps everything else isn't fine, but just not noticable yet, like a failing wheel bearing.

The better efficiency cold than warm is a puzzle. Could the engine be getting too much cooling from something like the thermostat getting stuck open? Excessive regen cycles bringing down the average? Going into open loop, but I would think that what throw a code.

Do you have access to a scangauge or torque app in order to get more data on what the car is doing?

[Bluebox]

Originally Posted by trollbait

Is the fuel slowly getting worse over time? Perhaps everything else isn't fine, but just not noticable yet, like a failing wheel bearing.

The better efficiency cold than warm is a puzzle. Could the engine be getting too much cooling from something like the thermostat getting stuck open? Excessive regen cycles bringing down the average? Going into open loop, but I would think that what throw a code.

Do you have access to a scangauge or torque app in order to get more data on what the car is doing?

No clear trend with time . I have checked the car over well (things like an Infrared Thermometer being very handy for checking disc temps and hub temps after a non braking run) - but all seems good. The cold thing is very odd - I agree , have not looked too hard yet , for example at where air intake is coming from exactly , and could there be a problem with warm air pick up somewhere ??
Car is warming up as I would expect , and sitting at a steady temp all the time (looks like about 85C on the gauge , but I have not checked it ... but steady is normally good)
No, I don't have any other data capturing "tools" ... yet !!.
Thanks for the constructive thoughts ... any more ??

[OliverGT]

Ok, let me throw in a real curve ball here. You say the car is calculating 80mpg and you are calculating 64mpg. That is a big difference, I know car displays can be off, but that is a large margin.

If you take 64mpg and convert to imperial mpg you get 77 imperial mpg, which is much closer to the 80 the car is calculating.

The only other things I can suggest is to speak to other owners see if they are seeing the same difference between the car display and calculated.

Hopefully between us all we can come up with some answers.

P.S. Do you have an instantaneous mpg display? What does this show at a constant 50 mpg, use cruise control if you have it for this test.

Oliver.