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Old 14th November 2011, 09:34   #16
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Default Re: How accurate is the distance to empty

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Originally Posted by dhanushs View Post
Not really. In most cars, it averages out the FE for the last 100 + kms or so.
Well, I differ. What you're talking of is the AVG. FE. That is calulated based on the Trip reading.

What I mentioned was - the real-time FE (the FE bar) which keeps varying literally every second.

The DTE is based on the real-time FE and hence, it too varies every second.


Quote:
DTE is a variable and depends upon the parameters.
  1. Average FE.
  2. Fuel remaining
And, that is precisely what I said
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Old 14th November 2011, 10:41   #17
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Default Re: How accurate is the distance to empty

DTE will not vary every second.

For example.. Try driving spiritedly, for a short stint of 1 km, and see if the DTE will recalibrate itself to the spirited driving FE. AFAIK, it will NOT.

But, if you continuously drive spiritedly for the last 1000 kilometers, then, the DTE for the next tankful will surely recalibrate with FE values for spirited driving.

Similarly, sedate driving for a short while will not increase (alter) that value.

Hence:
Quote:
Originally Posted by libranof1987 View Post
The DTE is based on the real-time FE and hence, it too varies every second.
Is not right.

P.S: This is the case in most cars I have seen (I guess the new city too). Please feel free to correct me if I'm wrong.

Last edited by dhanushs : 14th November 2011 at 10:52.
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Old 14th November 2011, 10:57   #18
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Default Re: How accurate is the distance to empty

Quote:
Originally Posted by libranof1987 View Post
Well, I differ. What you're talking of is the AVG. FE. That is calulated based on the Trip reading.

What I mentioned was - the real-time FE (the FE bar) which keeps varying literally every second.

The DTE is based on the real-time FE and hence, it too varies every second.




And, that is precisely what I said

I am not too sure about the car you are talking about, but in Fords I am sure that it is average FE over last 500 KMS. So if I did a highway trip recently, my full tank shows a range of 850 kms and stays so if I go on a highway trip again, but corrects itself to 750 kms by the half way mark for city driving conditions.
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Old 14th November 2011, 12:19   #19
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Default Re: How accurate is the distance to empty

The DTE at the time of refueling is calculated on your average fuel efficiency. But then as you drive along you will notice that the DTE changes(it may increase or decrease).

Now the changes in the DTE figure are based on the driving conditions. If you are stuck in traffic(read:driving on the lower gears) the DTE will drop.

Similarly if your car running on the highway in the economy zone(varies from car to car, but usually between 80 to 120 kmph) the DTE figure will rise for some time and then will start declining as per the distance you are traveling.

This is solely my observation on my Swift Diesel. DTE shower the range on 608 kms when I filled the tank but it actually went on for 695 kms.
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Old 14th November 2011, 13:55   #20
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Default Re: How accurate is the distance to empty

Quote:
Originally Posted by dhanushs View Post
DTE will not vary every second.

For example.. Try driving spiritedly, for a short stint of 1 km, and see if the DTE will recalibrate itself to the spirited driving FE. AFAIK, it will NOT.

But, if you continuously drive spiritedly for the last 1000 kilometers, then, the DTE for the next tankful will surely recalibrate with FE values for spirited driving.

Similarly, sedate driving for a short while will not increase (alter) that value.

Hence:

Is not right.

P.S: This is the case in most cars I have seen (I guess the new city too). Please feel free to correct me if I'm wrong.
In Punto the DTE varies based on the driving conditions of the last 5 - 10 kilometers. In fact if you drive spiritedly you can see the DTE going down and if you start driving sedately the DTE will climb back again.

From my personal experience the DTE is is very helpful for me since in Punto the DTE goes blank once it hits 50. I go and tank up my Punto when the DTE goes blank.
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Old 14th November 2011, 14:12   #21
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Default Re: How accurate is the distance to empty

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Originally Posted by nkg77 View Post
In Punto the DTE varies based on the driving conditions of the last 5 - 10 kilometers. In fact if you drive spiritedly you can see the DTE going down and if you start driving sedately the DTE will climb back again.

From my personal experience the DTE is is very helpful for me since in Punto the DTE goes blank once it hits 50. I go and tank up my Punto when the DTE goes blank.

In my Swift the first time, DTE went blank at 50 kms, was driving in city conditions. The second time it went blank at 40 kms, was driving on the highway at a steady speed of 100-110 kmph for past 10-15 kms.

So I think DTE surely considers the driving method for past few kilometers.
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Old 14th November 2011, 14:22   #22
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Default Re: How accurate is the distance to empty

Quote:
Originally Posted by nkg77 View Post
In Punto the DTE varies based on the driving conditions of the last 5 - 10 kilometers. In fact if you drive spiritedly you can see the DTE going down and if you start driving sedately the DTE will climb back again.
Hi ngk77,

By what % does the DTE vary, to the max?.

Thanks,

Dhanush


---------------------------------

Oh.. and Nishad, if it were instantaneous FE that is used for DTE calculations, then when the vehicle is not moving, with the engine running, the DTE should be '0' right?
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Old 14th November 2011, 14:29   #23
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Default Re: How accurate is the distance to empty

I will say as reliable as a ladies intuition (ladies please excuse). I will be surprised if the accuracy is much better than 15%.
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Old 15th November 2011, 13:36   #24
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Default Re: How accurate is the distance to empty

The DTE on my Laura, when tanked up varies anywhere between 550kms to 750kms. Thats depending on the last average it could return.

What I've heard is most modern cars are overtly cautious while showing DTE. Even when the car shows DTE as 10kms, it travels quite a distance. Of course, taking into consideration the style of driving and the amount of traffic.
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Old 15th November 2011, 13:40   #25
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Default Re: How accurate is the distance to empty

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Originally Posted by Swanand Inamdar View Post
What I've heard is most modern cars are overtly cautious while showing DTE. Even when the car shows DTE as 10kms, it travels quite a distance. Of course, taking into consideration the style of driving and the amount of traffic.
True. tried the same thing yesterday on the fabia. The DTE was showing KMS where as i was able to drive close to 25 Kms and still the fuel gauge indicator shows 2 points. This is quite a bit of confusion if we go with the DTE values.
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Old 15th November 2011, 13:51   #26
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Default Re: How accurate is the distance to empty

On my recently accquired Figo 1.2,. The DTE showed 486km or something on a tankful. Drove in 3rd/4th for some 15-18km on a very rolling terrain with full load and the DTE dropped to 401km. This looked like DTE sensor keeps tracking last driven kms.
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Old 15th November 2011, 19:07   #27
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Default Re: How accurate is the distance to empty

I use the DTE in my Punto as a good indicator of when to fill up. As others have mentioned the DTE indicator in Punto goes blank if the DTE is less than 50km. If DTE indication goes blank, I check it again after driving sedately for about 3-5km. If it doesn't come back up above 50, then it's time to refuel. I have once gone about 20-25km (on the highway) without refuelling after the DTE went blank.
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Old 15th November 2011, 19:58   #28
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Default Re: How accurate is the distance to empty

The DTE in my swift went blank at 40. Drove around 45kms after that. Still had some juice left as the tank was full in 37 liters. Tank capacity is 42 liters.
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Old 15th November 2011, 20:34   #29
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Default Re: How accurate is the distance to empty

Hi,
Does any car which shows DTE also show fuel remaining in litres in the MID?

Regards
Sutripta
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Old 15th November 2011, 21:22   #30
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Default Re: How accurate is the distance to empty

This is interesting indeed.

I have felt the DTE gauge on the city to be quite accurate. Ok, since it's always driven in the same style I guess it's easier for the techie-boards in the car to calculate the figures accurately.

While we are on this topic, does anyone know how they keep track of the fuel in an F1? Those guys in the pits seem to be getting very accurate figures. Since a lot of the tech used in the F1 trickles down to a road car, I guess the DTE too could be fine tuned.
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