[MaddyCrew]

Originally Posted by amalji

Question to Hyundai owners

1) Have you noticed such huge discrepancies for tank full to tank full mileage vs the average mileage shown on the console ?
2) If so, did you report it to Hyundai and what was their reaction ?

I own a 2012 Verna 1.6 Crdi. The deviation that I have noticed between the MID and Tank-Full to Tank-Full method has ranged between 2-3 kms max.

No offense, but I think we should first check if your friend is infact using the correct Tank-Full to Tank-Full calculation method. IMHO, there are quite a few variables that can affect this calculation - like the pump at which the fuel is filled, the fuel dispenser which is used, the actual time of the drive, the traffic conditions on the road, load levels in the car etc. While it is impossible for anyone to keep all these variables in check, effort should be taken to ensure that their values remain pretty much the same across the two comparison drives. An being someone who drives on MC Road almost every other weekend, I have to admit that the value of most of these variables can "fluctuate" quite a bit.

If your friend is more or less spot on with the calculation then he should get his car checked at the service center asap.

[amalji]

Originally Posted by veedub89

The values indicated by the mileage indicator should always be taken with a pinch of salt but the case you mention is certainly strange.
I am not sure what your friend will be able to accomplish by reporting this to Hyundai because I am quite sure that he would be given the cold shoulder.
A better alternative could be the Consumer Forum if your friend can build up a strong case.

yeah, 40% deviation from the actual value ( 20 - 14 / 14 ) is as good as cheating. There is no logical reasoning why that should occur when ECU calculates the mileage. If this is the case, then there is no use for the mileage calculator on the dashboard.

Originally Posted by arpanjha

Although a bit OT as I am not a Hyundai user, but my average FE indicator on the Punto never differs more than 1 to 1.5kpl, there might be some flaw with the sensors etc on the fluidic verna. Or maybe seriously Hyundai is taking its customers for granted.

1) Is it +/- 1.5 kmpl on the dashboard, or is it always +1.5 kmpl
2) 1.5 kmpl difference seems to be acceptable range for the error.

Originally Posted by 1100D

21kmpl shown on the console vs 15.5 actual is almost a 25% variation, too huge. Not sure if its just algorithm or something not working right.

That's an option as well. I'll ask him to report it to Hyundai anyway. We'll see what they say. Need to get to the root of it.

[S5157]

How was the calculation done after the diesel refill?Was it after auto cut-off to auto cut-off level or did he filled the tank upto filler cap before and after the trip.

My car takes 2+ liters of fuel after the auto-cut off and this could affect the calculation.

Just my 2 cents.

[aravind.anand]

My dad's Honda City i-Vtec keeps showing 12.3-13.1 kmpl for all the time, but whenever you calulate, its only about 10.5 kmpl. So we disregarded that mileage calculator for its terrible Math proficiency and stopped looking at it, completely. Does it mean that Honda cheats its customers?

[sa_kiran]

I have noticed these in my Honda City:
Mileage discrepancy: about 20% (actual 13.28, shown 15.9) - http://www.team-bhp.com/forum/indian...ml#post2942831
Speed: 7% more speed is shown by the analog dial, than that compared to either digital or GPS based.

So, it is a common practice for car manufacturers to show estimates convenient to them, though not correct.

[Trojan]

Hi,

I am an i10 user, faced a similar issue though not exactly the same, but can tell you what action I took and what was the response from Hyundai. The FE indicated by Hyundai for i10 Blue Drive never matched up and we were continuously getting horribly low FE of around 5-6KMPL on LPG against the stipulated 15-18 kmpl.
I raised it with the dealer during my first service, they mentioned it would improve (though no reasons were given except its a new car) well it didn't so I registered a complaint on Hyundai website and I did get a complaint number and got a prompt call from the dealer who asked me to come down for a mileage test - an hours drive with top-up to top-up and then calculate mileage.
In your friends case : there can be three possibilities

1. Error in fuel top-up, there can be a difference here, as fuel filled in the night/cooler hours will be lower in temperature hence more in volume/density compared to vice versa

2. Error in fuel top-up due to human error, e.g. filling fuel post auto-cut to reach a round figure or any other reason vs the return wherein fuel filled only till auto-cut

3. Calibration issue with the unit

I would suggest that your friend should report this on the company website and then go for a mileage check drive with the service personnel from Hyundai, that would help not only to clarify but also a documented complaint with the company.

Cheers!

[pganapathy]

Am just wondering how cars do the instant calculation. Would it be an algorithm based calculation based on gear, accelerator and revs. Or is it on the amount of fuel used and the distance actually travelled.

If it is the former, then anything that exceeds the conditions set in the algorithm will make the readings look optimistic. Greater weight than allowed for, bigger tyres due to an upgrade, tyre pressure, etc.

Thus I would expect the MID numbers to be off by a little bit. 5 kmpl seems a lot of difference though. We do need to appreciate though that the auto stop method is not the most accurate as there are occasionally differences of a few litres. Of course this does mean if more petrol is filled that the mileage number will come down, though if less filled at the beginning (less than full to start off) and then the tank is filled, the mileage amount will be worse, unfairly so. Of course if the MID numbers are consistently worse than the actual mileage, there may be an issue

[Omtoatom]

Anyway in a broader sense, a 10-15% variation is usually quite acceptable with MIDs. Generally the actual tends to be lesser. We too have a fluidic Verna in the family - however it usually returns FE readings well within that ceiling. In your case, since the deviation is almost 25%, it is obviously abnormal. You might want to get the car checked out by Hyundai.

[MAS]

I have heard about such incidents before. The ones that i know of are

- My friend who owns a Fluidic Verna complained about the high mileage shown in the MID vs the actual full tank to full tank method.

- There have been Verna owners who found the same high deviation in this forum itself. (unable to find the thread now. Will post a link)

Having said that, my New Fiesta's MID is pretty accurate with not much variation.

[ninjatalli]

Originally Posted by amalji

I'm composing this post based on inputs from my co-worker - Sojish Krishnan who owns a Fluidic Verna.

Where exactly does Kia come into picture?

And the title is quite misleading with respect to the discussion in hand. Your friend might have come to a conclusion based on his research, but the thread naming could be better stated, especially considering the discussion on hand.

[mercedised]

Not only Hyundai but all the manufacturers across India (I don't have information about abroad) are cheating in a way by quoting mileage figures which are almost unachievable in Indian traffic conditions.

[sarathlal]

As @DerAlte has mentioned in the initial posts of this thread, I also feel that the MID is the most accurate reading one can get regarding mileage.
Had tested this on the Civic along with the tank to tank method. For the five to six times, this was done, whatever was showing up in the MID was indeed holding true with my manual calculations as well, maybe with a difference of some decimal values.
For tank to tank, i was strictly following the 'stop filling when the pump auto cuts'. It is very difficult because the pump attendant will tend to press on the fuel even after it clicks out.

Am talking about the average mileage display and not the fancy 'instant mileage'.

[supremeBaleno]

Originally Posted by mercedised

Not only Hyundai but all the manufacturers across India (I don't have information about abroad) are cheating in a way by quoting mileage figures which are almost unachievable in Indian traffic conditions.

In India, you really can't charge Hyundai or any other manufacturer with cheating, because they are just bandying the figures from ARAI, which are way higher than what the car would get in normal usage. Hightime the publication of ARAI figures are stopped, because they mislead the layman into believing that he can actually get the 22.34kmpl (eg) that is mentioned. Ending almost always in huge disappointment.

[arpanjha]

Originally Posted by amalji

1) Is it +/- 1.5 kmpl on the dashboard, or is it always +1.5 kmpl
2) 1.5 kmpl difference seems to be acceptable range for the error.

.

It is generally +1.5 kmpl, i.e, the displayed figure is nearly 1 kmpl more or 1.5kmpl more than the actual figure i get

Originally Posted by pganapathy

Am just wondering how cars do the instant calculation. Would it be an algorithm based calculation based on gear, accelerator and revs. Or is it on the amount of fuel used and the distance actually travelled.

If it is the former, then anything that exceeds the conditions set in the algorithm will make the readings look optimistic. Greater weight than allowed for, bigger tyres due to an upgrade, tyre pressure, etc.

Thus I would expect the MID numbers to be off by a little bit. 5 kmpl seems a lot of difference though. We do need to appreciate though that the auto stop method is not the most accurate as there are occasionally differences of a few litres. Of course this does mean if more petrol is filled that the mileage number will come down, though if less filled at the beginning (less than full to start off) and then the tank is filled, the mileage amount will be worse, unfairly so. Of course if the MID numbers are consistently worse than the actual mileage, there may be an issue

As far as my knowledge goes about these FE indicators is that, firstly it is different technology used in different cars, but the most common one used is, they have a sensor at the throttle or the accelerator, which is I guess linked to the ECU, the ECU tells this sensor how much throttle is opened up, or how much the pedal is depressed, accordingly calculations are made how much fuel enters through the FI system, and then they are calibrated to the speed in which your car is going & the gear in which your car is in. It is pretty easy to assume that we require more power when the car is heavier and has more people in it or luggage in it, like, if you are with 4 passengers and some load, you may have to push your accelerator harder(depending upon the capability of the car) and if you are alone, normally for an ordinarily powered car the amount of throttle is lesser than the previously mentioned condition. I guess this is the way they calculate, this is what I have learnt from a few sources, people who have a better understanding may please explain the system for us to know the correct mechanism of this whole FE calculation system.

[amalji]

Originally Posted by MaddyCrew

I own a 2012 Verna 1.6 Crdi. The deviation that I have noticed between the MID and Tank-Full to Tank-Full method has ranged between 2-3 kms max.

No offense, but I think we should first check if your friend is infact using the correct Tank-Full to Tank-Full calculation method. IMHO, there are quite a few variables that can affect this calculation - like the pump at which the fuel is filled, the fuel dispenser which is used, the actual time of the drive, the traffic conditions on the road, load levels in the car etc. While it is impossible for anyone to keep all these variables in check, effort should be taken to ensure that their values remain pretty much the same across the two comparison drives. An being someone who drives on MC Road almost every other weekend, I have to admit that the value of most of these variables can "fluctuate" quite a bit.

If your friend is more or less spot on with the calculation then he should get his car checked at the service center asap.

Originally Posted by S5157

How was the calculation done after the diesel refill?Was it after auto cut-off to auto cut-off level or did he filled the tank upto filler cap before and after the trip.

My car takes 2+ liters of fuel after the auto-cut off and this could affect the calculation.

Just my 2 cents.

1) A deviation of 2-3 kms max seems to be still acceptable ( even though, I feel that the car manufacturer can easily give a more accurate figure than that based on the information ECU gets ). Here, the deviation is 40% flat!
2) Yes, he is using the correct tank full. He fills it near the brim every time. Doesn't go for the auto-cutoff.
3) By Pump at which fuel is filled, if you meant the quality of fuel, that shouldn't affect the ECU calculation, because all that matters for average mileage calculation is the amount of fuel supplied to engine and the total kms run. The quality of the fuel doesn't in anyway affect this parameter. The same is the case with the other parameters like actual time of the drive, the traffic conditions on the road, load levels in the car. Correct me, if I'm wrong.
4) One factor that can affect is the dispenser. But, on 2 trips, if it got affected from different pumps, then even that can be avoided. We'll consider the case of an error in the amount of fuel dispensed vs the actual fuel filled.
Suppose there is a 2 liter error ( which is a huge error ). Even then, the mileage shouldn't be offset by more than 5% especially for a single day drive.
5) Yes, I'll ask him to get his car checked at Hyundai.

Originally Posted by aravind.anand

My dad's Honda City i-Vtec keeps showing 12.3-13.1 kmpl for all the time, but whenever you calulate, its only about 10.5 kmpl. So we disregarded that mileage calculator for its terrible Math proficiency and stopped looking at it, completely. Does it mean that Honda cheats its customers?

If this is true for Honda cars, then yes, they seem to be cheating their customers. It seems to be a generic method adopted by all car manufacturers to up their customer's ego.

Originally Posted by sa_kiran

I have noticed these in my Honda City:
Mileage discrepancy: about 20% (actual 13.28, shown 15.9) - http://www.team-bhp.com/forum/indian...ml#post2942831
Speed: 7% more speed is shown by the analog dial, than that compared to either digital or GPS based.

So, it is a common practice for car manufacturers to show estimates convenient to them, though not correct.

What amazes me is that the error is always on one side. It never happens on the other side.

Originally Posted by Trojan

Hi,

I am an i10 user, faced a similar issue though not exactly the same, but can tell you what action I took and what was the response from Hyundai. The FE indicated by Hyundai for i10 Blue Drive never matched up and we were continuously getting horribly low FE of around 5-6KMPL on LPG against the stipulated 15-18 kmpl.
I raised it with the dealer during my first service, they mentioned it would improve (though no reasons were given except its a new car) well it didn't so I registered a complaint on Hyundai website and I did get a complaint number and got a prompt call from the dealer who asked me to come down for a mileage test - an hours drive with top-up to top-up and then calculate mileage.
In your friends case : there can be three possibilities

1. Error in fuel top-up, there can be a difference here, as fuel filled in the night/cooler hours will be lower in temperature hence more in volume/density compared to vice versa

2. Error in fuel top-up due to human error, e.g. filling fuel post auto-cut to reach a round figure or any other reason vs the return wherein fuel filled only till auto-cut

3. Calibration issue with the unit

I would suggest that your friend should report this on the company website and then go for a mileage check drive with the service personnel from Hyundai, that would help not only to clarify but also a documented complaint with the company.

Cheers!

Points - 1 and 2 can be ignored because of the huge discrepancy ( 40 % )
Point 3 will have to be checked out.

Originally Posted by pganapathy

Am just wondering how cars do the instant calculation. Would it be an algorithm based calculation based on gear, accelerator and revs. Or is it on the amount of fuel used and the distance actually travelled.

If it is the former, then anything that exceeds the conditions set in the algorithm will make the readings look optimistic. Greater weight than allowed for, bigger tyres due to an upgrade, tyre pressure, etc.

Thus I would expect the MID numbers to be off by a little bit. 5 kmpl seems a lot of difference though. We do need to appreciate though that the auto stop method is not the most accurate as there are occasionally differences of a few litres. Of course this does mean if more petrol is filled that the mileage number will come down, though if less filled at the beginning (less than full to start off) and then the tank is filled, the mileage amount will be worse, unfairly so. Of course if the MID numbers are consistently worse than the actual mileage, there may be an issue

It should be the later, atleast for the average mileage figures. ECU should be having information about the amount of fuel supplied and the distance covered. If it doesn't want to use this data for average mileage calculation, then the programmer doesn't really want to show the true value.

Originally Posted by Omtoatom

Anyway in a broader sense, a 10-15% variation is usually quite acceptable with MIDs. Generally the actual tends to be lesser. We too have a fluidic Verna in the family - however it usually returns FE readings well within that ceiling. In your case, since the deviation is almost 25%, it is obviously abnormal. You might want to get the car checked out by Hyundai.

Actual mileage - 15.x
Mileage on MID - 21.x
==> Deviation = ( 21 - 15 / 15 ) * 100 = 40%

It's quite abnormal.

Originally Posted by MAS

I have heard about such incidents before. The ones that i know of are

- My friend who owns a Fluidic Verna complained about the high mileage shown in the MID vs the actual full tank to full tank method.

- There have been Verna owners who found the same high deviation in this forum itself. (unable to find the thread now. Will post a link)

Having said that, my New Fiesta's MID is pretty accurate with not much variation.

Thanks for this info. I'll search around as well.

Originally Posted by ninjatalli

Where exactly does Kia come into picture?

And the title is quite misleading with respect to the discussion in hand. Your friend might have come to a conclusion based on his research, but the thread naming could be better stated, especially considering the discussion on hand.

True. I started the thread after reading the article on Hyundai and KIA cheating its customers. So, it seems to have affected the subject of the thread.

Originally Posted by mercedised

Not only Hyundai but all the manufacturers across India (I don't have information about abroad) are cheating in a way by quoting mileage figures which are almost unachievable in Indian traffic conditions.

If that's the case, we at team-bhp need to take up this and thrash whoever is doing that. It cannot be that when dealing with Indians, no one need to think of ethics!

Originally Posted by sarathlal

As @DerAlte has mentioned in the initial posts of this thread, I also feel that the MID is the most accurate reading one can get regarding mileage.
Had tested this on the Civic along with the tank to tank method. For the five to six times, this was done, whatever was showing up in the MID was indeed holding true with my manual calculations as well, maybe with a difference of some decimal values.
For tank to tank, i was strictly following the 'stop filling when the pump auto cuts'. It is very difficult because the pump attendant will tend to press on the fuel even after it clicks out.

Am talking about the average mileage display and not the fancy 'instant mileage'.

Quite true. It is logically very much possible for the ECU to calculate this value with +/- 10% error. Any error beyond that and there is something fishy!

Originally Posted by sarathlal

As @DerAlte has mentioned in the initial posts of this thread, I also feel that the MID is the most accurate reading one can get regarding mileage.
Had tested this on the Civic along with the tank to tank method. For the five to six times, this was done, whatever was showing up in the MID was indeed holding true with my manual calculations as well, maybe with a difference of some decimal values.
For tank to tank, i was strictly following the 'stop filling when the pump auto cuts'. It is very difficult because the pump attendant will tend to press on the fuel even after it clicks out.

Am talking about the average mileage display and not the fancy 'instant mileage'.

Originally Posted by DerAlte

On the other hand, MIDs in modern cars report consumption figures calculated by the injection ECU (there are lots of ECUs in a car like Camry). The injection ECU calculates petrol consumed by summing up injection time from EACH injection. The injection time is how long the injector was kept open for 1 stroke; rail pressure is assumed constant. Total Injection Time, multiplied by the reference volume / unit time (calculated in the vehicle test lab using ultra-accurate instruments), gives the petrol consumed over a period of time. Divide the distance traveled during the same time (this comes from the transmission) by the petrol volume, and one gets the 'X litres / 100Km.' figure.

The petrol consumed as measured by the ECU is accurate down to microlitres. Your measurement has a potential inaccuracy of 2 digit milliliters at least! So which method is more accurate?

If what you said is true, if the car manufacturers really want, they can do the calculation correctly. When we do tank full to tank full fills especially with 40 liters or so, the error that we can expect is < 5%
If the MID values are offset to the range of 40%, then there is some serious stupidity or deliberate modification done to the way ECU calculates mileage figures. And the fact that it always shows more mileage and never less mileage surprises me.
And it seems, it's not just with Hyundai or KIA. Most car manufacturers seem to be doing the same.

Originally Posted by supremeBaleno

In India, you really can't charge Hyundai or any other manufacturer with cheating, because they are just bandying the figures from ARAI, which are way higher than what the car would get in normal usage. Hightime the publication of ARAI figures are stopped, because they mislead the layman into believing that he can actually get the 22.34kmpl (eg) that is mentioned. Ending almost always in huge disappointment.

In fact, ARAI does give an approximate figure. What I normally do is to expect 70% of what ARAI claims for normal driving ( not the highway long trips ). It has worked fine in most cases. And most people who buy the car knows that the ARAI testing is under ideal conditions under no load. But, the discrepancy in average mileage calculation by the MID is way too high even after having the advantage of having all the data ready inside ECU! And this doesn't seem like a Hyundai or KIA issue. Every manufacturer seems to be trying to fool the customer which even questions the usefulness of the MID