[mayukh]

Originally Posted by nairrk

7/7.5 KMPL is too low. so it is better to check another couple of tankful readings prior you take the FE calculation.
DTE sometime show correctly. In my car, it is always correct as I have seen several times that when it comes to 80/81/82, the low fuel warning light glows. According to FORD manuel once the low fuel warning light comes, then the car will have fuel to go about 80kms. So DTE figure seems correct?

Yes, I think something is going wrong. When I did the tankfull today, the DTE showed 360. That means, 8 KMPH (360/45). At that time, the needle also pointed to full tank

May be I have to do some more tankfull calculations after filling the petrol from a different fuel station.

[Gilead]

My DTE used to be fairly accurate until this week. I changed the tire pressure in my tires and it has gone bonkers after that. Initially it was showing a low reading as some tires were under-inflated. They were then over inflated and the DTE shot up. Finally I got the right pressure in my tires, the DTE is showing large variations whenever I park the car at signals. It's like the DTE is calculating the avg of the last 50 or 100 kms and it's unable to decide which is the correct one due to all the tire pressure and resulting FE changes.

I usually get 425-440 on the DTE after a full tank. This is on the 1.6S which runs on larger and broader tires.

[mayukh]

Originally Posted by Gilead

My DTE used to be fairly accurate until this week. I changed the tire pressure in my tires and it has gone bonkers after that. Initially it was showing a low reading as some tires were under-inflated. They were then over inflated and the DTE shot up. Finally I got the right pressure in my tires, the DTE is showing large variations whenever I park the car at signals. It's like the DTE is calculating the avg of the last 50 or 100 kms and it's unable to decide which is the correct one due to all the tire pressure and resulting FE changes.

I usually get 425-440 on the DTE after a full tank. This is on the 1.6S which runs on larger and broader tires.

360 against 425-440??? I also remember that during the last tank full, it showed around 380.

Whom to blame now? My car or my driving style or my oil station?
Gilead or anyone, can you atleast confirm whether my driving style (mentioned 2-3 posts above) is correct or not?

I forgot to mention too that I do not switch off the engine at all at traffic signals, even if it of longer durations (60 sec & more). May be I have to change that bad habit also.

[Gilead]

Mayukh, it can't be your driving style as you have already said it's sedate. But don't lug the engine. I find that I get better FE only if I drive above 2K RPM. I got 9.2 during a period when I put in about 60 odd kms at the race track mostly in 2nd or 3rd gear with RPMs always above 3K. So ripping the car reduced the FE from 9.4 to 9.2 only.

FE also depends on the traffic condition. If it's B2B traffic, FE will take a hit but not to the extent you are talking about like 7 or 8. I don't switch off the engine at the traffic lights and I don't plan to either in order to eke out another 1 KM or 2. It's far too hot here to be sitting around without AC and I didn't spend nearly 8 lacs on a car to sweat like a pig inside.

The biggest culprits usually are adulterated fuel and under-inflated tires. Take care of both and your FE will be close to 10 or more.

[nairrk]

@mayukh
when you fuel upto the full tank, the DTE must show anything over 440/450 (I have read reports that some people are getting even better). It has nothing to do with your driving style (FE is concerned with driving style). May be your car DTE is not properly sensing how much fuel the tank have??

[mayukh]

Originally Posted by Gilead

Mayukh, it can't be your driving style as you have already said it's sedate. But don't lug the engine. I find that I get better FE only if I drive above 2K RPM. I got 9.2 during a period when I put in about 60 odd kms at the race track mostly in 2nd or 3rd gear with RPMs always above 3K. So ripping the car reduced the FE from 9.4 to 9.2 only.

The biggest culprits usually are adulterated fuel and under-inflated tires. Take care of both and your FE will be close to 10 or more.

Ok I will take care not to lug the engine. I think driving between 2000-2500 rpm will help. Am I correct? Remember I have just 800 KM on the ODO.

Adulterated fuel: I will change my petrol station next time.
Under-inflated tires: I maintain 30 in front & 35 in back. I do check every 20-22 days. May be I have to check from independent shops again?

Originally Posted by nairrk

@mayukh
when you fuel upto the full tank, the DTE must show anything over 440/450 (I have read reports that some people are getting even better). It has nothing to do with your driving style (FE is concerned with driving style). May be your car DTE is not properly sensing how much fuel the tank have??

I also felt that the DTE is not showing it properly. But at least the petrol should not have vaished to give me a FE of 7. I have to again ask the service guys to look into it also.

[shajufx]

Originally Posted by Gilead

Initially it was showing a low reading as some tires were under-inflated. They were then over inflated and the DTE shot up.

Gil, thats news to me now. Does the DTE has any connection to tire pressure at all ? I really doubt. DTE is not accurate on any fiesta as far as I understand (I have 7 fiestas in my compound). Its only an indication. Its more accurate when its idle or parked. Just my feel, open to correction.

Originally Posted by mayukh

Whom to blame now? My car or my driving style or my oil station? Gilead or anyone, can you atleast confirm whether my driving style (mentioned 2-3 posts above) is correct or not?.

Mayukh, unless we sit with you on a drive, we wont be able to judge if your driving style is correct or not ! What if you leave a heavy brick on the accelator pedal and operate only the break and clutch while you drive ? So, it depends on many aspects.

About the engine off action at the signals, I have never done that till today and its not possible to do it in the heat. Some people dont mind switching off the engine at 5 places in 15 mts (peak hours in bangalore will make you do that). I cant do that and I will never do that. Reason is very simple: I cant take the heat when you switch off the AC in the peak hours even if its for 2 mts. Its totally out of question when you have your family specialy kids.

If comfort was not my priority, I would have spent less than 2 laks and bought an old open Jeep which can also serve my Point A to B movement.

[mayukh]

Originally Posted by shajufx

Mayukh, unless we sit with you on a drive, we wont be able to judge if your driving style is correct or not ! What if you leave a heavy brick on the accelator pedal and operate only the break and clutch while you drive ? So, it depends on many aspects.

Thanks Shaju. Now can I have the pleasure to invite you here in Kolkata so that you can help me with my driving style? Please do come. I will ensure a royal bengali stay here for you.

On a serious note, I may have to catch up with some guys here during the Team-BHP Kolkata meet (17-18 April) to help me with my driving style.

But again, my invitation from you still holds good.

[nairrk]

@
ha, shaju, when you are driving down to Kolkatta!?
You have now got a great invitation with Royal bengali Treat - Dont miss it?

[Gilead]

Originally Posted by mayukh

Ok I will take care not to lug the engine. I think driving between 2000-2500 rpm will help. Am I correct? Remember I have just 800 KM on the ODO.

I think most petrol bunks have improperly calibrated machines. Best to get air filled at a tire dealer.

Originally Posted by shajufx

Gil, thats news to me now. Does the DTE has any connection to tire pressure at all ? I really doubt. DTE is not accurate on any fiesta as far as I understand (I have 7 fiestas in my compound). Its only an indication. Its more accurate when its idle or parked. Just my feel, open to correction.

Tire pressure has an effect on the rolling resistance which in turn has an effect on the FE which in turn has an effect on the DTE. Try driving with tire pressure at 24 or 25 all around and you will see what I am talking about. The Fiesta DTE is an avg. of the last 50 or 100 kms and not instantaneous as far as I understand.

[shajufx]

Originally Posted by mayukh

I will ensure a royal bengali stay here for you.

Originally Posted by nairrk

You have now got a great invitation with Royal bengali Treat - Dont miss it?

Mayukh, thanks for the good heart, on a serious note, can I have the validity of invitation for 1 year ? I always wanted to visit Kolkatta where lot of sharp brains exist (writers, poets, visionaries etc.)

Originally Posted by Gilead

Tire pressure has an effect on the rolling resistance which in turn has an effect on the FE which in turn has an effect on the DTE.

Which in turn has an effect on the driver which in turn has an effect on the wife which in turn has an effect on the family life too !!!!

Now my simple doubt: Is not the DTE based on a floater device inside the fuel tank than some computer calculation ? I agree higher segment cars (BMW, Merc etc) have a computer calculation of fuel levels. But do you think Ford can afford such an advanced device in a low cost sedan ? I think we have some members in the manufacturing plant itself, they could throw some technical knowledge here. Kiku are you there ? Kiku please respond to this within 24 hours or I will have to request the mods to ban you here !

[mayukh]

Originally Posted by shajufx

Mayukh, thanks for the good heart, on a serious note, can I have the validity of invitation for 1 year ? I always wanted to visit Kolkatta where lot of sharp brains exist (writers, poets, visionaries etc.)

Yes. Shaju. It will be valid for as many years as you want. I can say it's valid for other members here too.

Sharp brains? All gone down to the drains of politics.

[sanjayc]

There we go again here on the DTE...I thought this was discussed to death in the closed thread.

DTE is definitely linked with the driving characteristic and the amount of fuel avlbl. By driving characteristic I mean historical trend (amount of distance travelled in the recent past vs fuel consumed).

Once some instruments are avlbl in the car to measure the amount of fuel availalble at point in time, then it is no rocket science to predict the DTE, by continously monitoring the total distance travelled and total fuel consumed from your last cold start. Obviously to arrive at a fairly accurate estimate, various other parameters will be taken into account like when to reset the various parameters, last how many kms to be taken for arriving at a FE, how much spare fuel will be left out of the equation etc etc.

Regarding erratic DTE behaviour, my guess is it has something to do with resetting of the values. Taking all things into consideration, I am again guessing this reset happens when a tank full is done. Assuming that the fuel amount measuring device have various so-called "trigger-points" which when crossed provide the amount of fuel left, it is easy to guess Mayukh's issue. Some trigger points definitely should be there since I cannot think of a device which can predict the actual quantity of fuel left to the last drop. In this case, If Mayukh filled up 38l but actuall trigger point would have been somewhere aroung 35l, the DTE is assuming only 35l is avlbl. Hence, IMO, it is always best to fill up till the second cut-off and then some more, just to be sure.

Mayukh, just wait for another tank fill to come to right calculation. Anyway your 800 on ODO means highway drives have hardly materialised. You should be getting at least 8-9, no matter what driving style. In city, Ford itself claims 10 and highway 14.

And yes, ignore the messages regarding switching off engine/ac at signals..those are for trucks/vans/buses/autos. As someone else said, my ac on/off switch is controlled by the ignition key.

Are u using System-G..maybe you can try the same every alternate tank fill. Kolkata is so polluted that maybe the engine itself is getting polluted
Now that your car is new, try with 4-5 different fuel stations of various brands and settle for the pump where you are getting most bang for your buck.

Originally Posted by shajufx

Gil, thats news to me now. Does the DTE has any connection to tire pressure at all ? I really doubt.

DTE is just another way to indicate the FE. Anything which affects the FE will have a impact on the DTE. This does not mean or require the DTE instrument to have a sensor in the tyre to measure the tyre pressure, or wire up the brake to measure how much pressure you are applying on the brake;-}

Originally Posted by shajufx

Is not the DTE based on a floater device inside the fuel tank than some computer calculation ?

Both actually..floater device or not, as long as some mechanical device is there to accurately estimate the remaining fuel, calculating the DTE/FE etc on a real time basis via some software can be done even by those guys who have just completed a library management team-project in Basic/VB/Cobol.
=========================

OK, now the million dollar question..are u guys planning to empty the tank fully before filling up the BS IV fuel from 1st April. I am afraid a BS III/IV cocktail may give my Fiesta a high & hangover!!

=========================

[sanjayc]

Originally Posted by nairrk

In my car, it is always correct as I have seen several times that when it comes to 80/81/82, the low fuel warning light glows. According to FORD manuel once the low fuel warning light comes, then the car will have fuel to go about 80kms. So DTE figure seems correct?

Nairji, the warning light is programmed to light up as soon as the DTE shows 80..it does not mean the DTE of 80 reading is accurate.

Try this simple experiment:
Next time your DTE shows between 75-80 & the warning come up, stop the car if you can. Next time you start the car after some considerable rest, the DTE may show 85-90 and the warning light will remain off. Does that mean some extra fuel is poured in the tank? No.

Another experiment to try is to mark the fuel guage needle point with a marker as soon as the warning lamp comes on. Post tank full, check if the needle is exactly at the same point when it comes on again. If yes, thank your government and the place you live..it has more to do with sedate driving conditions than sedate driving and DTE accuracy.

You might be getting more accurate figures if your driving conditions are more constant than us guys where condition changes to worst to most worse from one signal to the next signal!

DTE is only an approximation. However, it does indicate if one is a bad driver or good, provided all other driving/fuel/road conditions are similar.

[shajufx]

Originally Posted by sanjayc

OK, now the million dollar question..are u guys planning to empty the tank fully before filling up the BS IV fuel from 1st April. I am afraid a BS III/IV cocktail may give my Fiesta a high & hangover!!

Is it applicable only in Chennai ? I havent heard anyone talking about such a thing here. May be nobody gives any importance ! So whats this BSIV fuel actually ? More kerosene added ?