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Old 14th September 2013, 23:12   #631
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Originally Posted by Grr7 View Post
Greetings to tbhpians,

3. The car is being driven with the lightest accelerator pedal, correct gear changing and no idling with a/c on. The gears are being changed anywhere from 1400-1900 rpm taking care of no engine lugging at any time.
Isn't gear shifting at 1400rpm bit low? Part the gear change it would drop to 1000 rpm which would be lugging the engine. I change gears at sharp 2000 rpm.

Is the clutch fine and working as it should?

Change Air filter every 10K kms and get it cleaned with high pressure air at every 5K kms.

What are the tyre pressures you maintain? This also could be affecting efficiency.

Anurag.
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Old 27th September 2013, 23:00   #632
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Re: ARTICLE: How to get the maximum Fuel Efficiency

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Originally Posted by GTO View Post
• Minimise Idling: If your car is going to be stationary for an extended period of time, switch the engine off.
.
Hi GTO,

Some people debate that frequent switching ON/OFF the engine draws more fuel than keeping it in idling for sometime, in an article few years ago in Bangalore times I read that when starting an engine it consumes same amount of fuel equivalent to 40 seconds of Idling, is it true?

If not can you suggest how many seconds can one idle instead of switching ON/OFF the engine.
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Old 28th September 2013, 13:08   #633
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Re: ARTICLE: How to get the maximum Fuel Efficiency

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Originally Posted by slamnos View Post
I read that when starting an engine it consumes same amount of fuel equivalent to 40 seconds of Idling, is it true?
Differ's with engine's and your running. However, for normal city driving, with most small displacement engines (read--> ford's tdci, fiat's mjd's, renault's dci), if you estimate that you are going to idle for more than 20s, you can turn your engine off.

Thanks,
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Old 4th October 2013, 05:01   #634
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If not can you suggest how many seconds can one idle instead of switching ON/OFF the engine.
It would be best if you switch the engine Off when the signal time is greater than 30 seconds. Longer time is useless and waste of fuel.

Next question would be suffocation due to NO AC. If AC usage is must, then one can bear the blower in circulation mode for 20-30 seconds post which the AC will be ON.

Moreover longer idling is also bad for the engine due to no effective cooling since the car is stationary and the heat build up is greater (no air movement). In a moving car the heat build up would be lower due to better heat dissipation.

Since I use the OBD II reader I found that keeping the constant at 100 kmph, the coolant temperature is about 85-87 degree C but while idling greater than 30 seconds the temperature goes upto 92 degree C (This idling after a normal a city + highway drive). Will post screen shots soon for the idling condition.

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Originally Posted by Simple_car View Post

Differ's with engine's and your running. However, for normal city driving, with most small displacement engines (read--> ford's tdci, fiat's mjd's, renault's dci), if you estimate that you are going to idle for more than 20s, you can turn your engine off.
+1.

Anurag.

Last edited by a4anurag : 4th October 2013 at 05:04.
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Old 29th July 2014, 14:31   #635
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Fuel Efficiency PLUMMETS !!! in my Hyundai Verna 1.5 CRDI VGT ('07 Model)

I have a Hyundai Verna 1.5 CRDI VGT. I bought it in Feb'07 and till date have clocked around 70,000 kms. It runs on Michelin XM 2 (tyre/wheel size being 185/65/14)

Problem :
The fuel efficiency over the last one year has been around 10.0 to 10.75 kms/ltr, which in itself is very poor, right ?? I was shocked to see a figure of 9.85 kms/ltr when I checked last, which was about a week back

I don't have any real technical understanding of the innards of automobiles, all I know I have learned from forums like this and from reading auto magazines

Having said that, I have tried to maintain my humble car as well as I could by
1. Getting it serviced on time, every time
2. Maintaining correct tyre pressure at all times
3. Driving sedately most of the time (till I control my right foot any further !!);
changing into higher gears at the earliest without lugging the engine
4. Using fuel injector cleaners and fuel additives from Bardahl periodically
5. Last but not the least, in the car's last service, I opted for the "OWS Goodies
+ Fully Synthetic Engine Oil"; i.e. engine flush --> engine protectorant -->
engine oil --> 360 fuel treatment

I'd like to believe I'm doing the "right things". However, I have noticed that over the last 6-9 months the fuel efficiency of my car has been going southwards with alarming consistency !!?? On multiple occasions I have sought the help of the A.S.S. but they couldn't figure things out. I have even taken my car to a well known tuning specialist (no names taken), but, to no avail

I must add that after adding the OWS products the engine is revving really freely and is fabulous to drive. I kept asking myself why I didn't do this earlier

I request all the Auto Pundits out there (Verna owners and otherwise) to help me with inputs which will help me increase my car's fuel efficiency to atleast 13 kms/ltr (in the city). That would make me very happy

Apologies for my rather long post. Didn't know how else to convey my problem

Thanks in advance !!

Mod Note: Post Edited. Smiley usage is restricted to two per post on Team-BHP. Please do NOT use more than 2 smileys in a post.

Last edited by Rudra Sen : 29th July 2014 at 16:28.
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Old 29th July 2014, 15:10   #636
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Re: Fuel Efficiency PLUMMETS !!! in my Hyundai Verna 1.5 CRDI VGT ('07 Model)

There are some external factors too involved in fuel efficiency.So some queries .

1)Are you filling fuel from the same pump? .
Chances are there can be fraud. Change the pump and see.
2)Anybody else drives the vehicle?(Driver ?)
Drivers can be mischievous.
3)Have you checked with an OBD scanner ?
Issue with the engine that the mechanic cannot see. There can be pressure leakage or compression failure too.

Hope others in the forum can pin point the issue.
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Old 29th July 2014, 17:40   #637
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Re: Fuel Efficiency PLUMMETS !!! in my Hyundai Verna 1.5 CRDI VGT ('07 Model)

Quote:
Originally Posted by Amitabh375 View Post
I have a Hyundai Verna 1.5 CRDI VGT. I bought it in Feb'07 and till date have clocked around 70,000 kms. It runs on Michelin XM 2 (tyre/wheel size being 185/65/14)

Problem :
The fuel efficiency over the last one year has been around 10.0 to 10.75 kms/ltr, which in itself is very poor, right ?? I was shocked to see a figure of 9.85 kms/ltr when I checked last, which was about a week back

I don't have any real technical understanding of the innards of automobiles, all I know I have learned from forums like this and from reading auto magazines

Having said that, I have tried to maintain my humble car as well as I could by
1. Getting it serviced on time, every time
2. Maintaining correct tyre pressure at all times
3. Driving sedately most of the time (till I control my right foot any further !!);
changing into higher gears at the earliest without lugging the engine
4. Using fuel injector cleaners and fuel additives from Bardahl periodically
5. Last but not the least, in the car's last service, I opted for the "OWS Goodies
+ Fully Synthetic Engine Oil"; i.e. engine flush --> engine protectorant -->
engine oil --> 360 fuel treatment

I don't know what's the FE of a verna. But please check the following:
  • Air filter-Clogged ones will drastically reduce FE
  • Get injector cleaning done in the ASS. I don't know how much additives help.
  • Get your fuel pump checked. Fuel is often of bad quality and clogging in fuel pump can result in poor FE.
  • Take a second opinion and do a decarbonisation if required.
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Old 29th July 2014, 19:37   #638
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Re: Fuel Efficiency PLUMMETS !!! in my Hyundai Verna 1.5 CRDI VGT ('07 Model)

Quote:
Originally Posted by Amitabh375 View Post

Problem: The fuel efficiency over the last one year has been around 10.0 to 10.75 kms/ltr, which in itself is very poor, right ?? I was shocked to see a figure of 9.85 kms/ltr when I checked last, which was about a week back
I say check the air filter + fuel filter and if not changed from long then get it changed.

Do try and change your pump and see if there is a change in economy.

Anurag.
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Old 29th July 2014, 21:20   #639
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Re: Fuel Efficiency PLUMMETS !!! in my Hyundai Verna 1.5 CRDI VGT ('07 Model)

Quote:
Originally Posted by Amitabh375 View Post
The fuel efficiency over the last one year has been around 10.0 to 10.75 kms/ltr, which in itself is very poor, right ?? I was shocked to see a figure of 9.85 kms/ltr when I checked last, which was about a week back
Before you draw any conclusion do you mind letting us know how you obtain this data? How do you measure this? Do you get the reading from the multi display on the dashboard? If so, try this for a real accurate measurement; Note the mileage when you fill up with petrol and check the mileage again when you fill up next time, note very carefully how much petrol goes in. (Or use the day counter.)
This will give you a more reliable reading. Especially if you take the readings over 3-5 full refills and add up the liters. That will give you an idea of the real FE.

The multi displays (nearly) always have an error. There is another thread on the forum where this is discussed in detail.

So, if the above figures are the real ones, and not just the data displayed in your dashboard I would check the following, because it only take fives minutes and can cause problem:
- air filter needs to be clean as pointed out.
- same for the fuel filter, you can't really check, but they are usually easy and cheap to replace and if it has not been done before you might as well do it now.

These are the two most consistent factors that will result in poor FE, without really affecting engine performance. (you did not mention it, so I sort of assumed that the car/engine does run fine otherwise?)

- Not sure what particle filter your car has if any? But that is a known cause too for poor FE when these filters get clogged too.

Next
- Get the car hooked up to a proper OBD analyzer, check for any codes. Most OBD analyzers will also give you a host of parameters whilst running the engine, so you can get a good sense of what goes on in the engine.

One other thing you can check visually, does you car/engine produces a lot, or at least more than before, black smoke? If so, that could be an important clue.

Jeroen
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Old 30th July 2014, 10:38   #640
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Quote:
Originally Posted by commonman View Post
There are some external factors too involved in fuel efficiency.So some queries .

1)Are you filling fuel from the same pump? .
Chances are there can be fraud. Change the pump and see.
2)Anybody else drives the vehicle?(Driver ?)
Drivers can be mischievous.
3)Have you checked with an OBD scanner ?
Issue with the engine that the mechanic cannot see. There can be pressure leakage or compression failure too.

Hope others in the forum can pin point the issue.
To answer your questions Commonman
1. Yes, I fill fuel from the same bunk. Will try another one and see the difference
2. Driven 95% by me, balance by wifey
3. The A.S.S. technician did use an OBD Scanner sometime back but it didn't throw up anything. Will try again

Cheers

Quote:
Originally Posted by D4D View Post
I don't know what's the FE of a verna. But please check the following:
  • Air filter-Clogged ones will drastically reduce FE
  • Get injector cleaning done in the ASS. I don't know how much additives help.
  • Get your fuel pump checked. Fuel is often of bad quality and clogging in fuel pump can result in poor FE.
  • Take a second opinion and do a decarbonisation if required.

Thanks a ton for your inputs
1. FYI I had the oil/fuel/air filters replaced during the last service (about 45 days back)
2. I will surely get the fuel pump checked and fuel injectors cleaned. Been planning to get them cleaned but not got around to doing so
3. Will also get the engine decarbonised

Cheers

Quote:
Originally Posted by Jeroen View Post
Before you draw any conclusion do you mind letting us know how you obtain this data? How do you measure this? Do you get the reading from the multi display on the dashboard? If so, try this for a real accurate measurement; Note the mileage when you fill up with petrol and check the mileage again when you fill up next time, note very carefully how much petrol goes in. (Or use the day counter.)
This will give you a more reliable reading. Especially if you take the readings over 3-5 full refills and add up the liters. That will give you an idea of the real FE.

The multi displays (nearly) always have an error. There is another thread on the forum where this is discussed in detail.

So, if the above figures are the real ones, and not just the data displayed in your dashboard I would check the following, because it only take fives minutes and can cause problem:
- air filter needs to be clean as pointed out.
- same for the fuel filter, you can't really check, but they are usually easy and cheap to replace and if it has not been done before you might as well do it now.

These are the two most consistent factors that will result in poor FE, without really affecting engine performance. (you did not mention it, so I sort of assumed that the car/engine does run fine otherwise?)

- Not sure what particle filter your car has if any? But that is a known cause too for poor FE when these filters get clogged too.

Next
- Get the car hooked up to a proper OBD analyzer, check for any codes. Most OBD analyzers will also give you a host of parameters whilst running the engine, so you can get a good sense of what goes on in the engine.

One other thing you can check visually, does you car/engine produces a lot, or at least more than before, black smoke? If so, that could be an important clue.

Jeroen

Hey Jeroen

Thanks for taking time out man and helping me out. Appreciate it !!

1. I calculate my engine's fuel efficiency the manual way, i.e. by filling the tank, driving till the tank is 1/2 or 3/4 empty, then filling the tank again, dividing what the trip meter shows by litres filled. Am I doing it right ??
2. Both the air & fuel filters were replaced during the last service (about 45 days back)
3. I will take the help of an OBD Scanner
4. Yes, my car does emit black smoke upon slightly hard acceleration, especially when accelerating in the 2nd gear. It used to emit hell of a lot of black smoke a few years back (was embarrassing). I had asked the A.S.S. to look into it. Don't remember what exactly they did, but, it reduced dramatically. Just how would this be linked a drop in FE ??

Cheers

Last edited by Rudra Sen : 30th July 2014 at 11:07.
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Old 30th July 2014, 12:28   #641
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Re: ARTICLE: How to get the maximum Fuel Efficiency

Quote:
Originally Posted by Amitabh375 View Post

1. I calculate my engine's fuel efficiency the manual way, i.e. by filling the tank, driving till the tank is 1/2 or 3/4 empty, then filling the tank again, dividing what the trip meter shows by litres filled. Am I doing it right ??
2. Both the air & fuel filters were replaced during the last service (about 45 days back)
3. I will take the help of an OBD Scanner
4. Yes, my car does emit black smoke upon slightly hard acceleration, especially when accelerating in the 2nd gear. It used to emit hell of a lot of black smoke a few years back (was embarrassing). I had asked the A.S.S. to look into it. Don't remember what exactly they did, but, it reduced dramatically. Just how would this be linked a drop in FE ??
Good, so you are doing the best way to calculate FE.
I would suggest to get it hooked up to an OBD analyzer, preferably a car/model specific one and have a competent mechanic make a diagnosis on the live data and or any codes he/she might find. I understand that last time there were no codes. Still, a good OBD analyzer is able to take a wide range of engine performance readings and a good competent mechanic should be able to make a diagnosis, or at least exclude a lot stuff.

I would also suggest not to do anything to the car (e.g. decarbonisation etc) before you have done the OBD code + live data analyser thing.

Black smoke can be an indication of incomplete ignition process. Meaning that not all fuel gets combusted in the most efficient way. Or to put it differntly, under those circumstance you are not getting the correct bang for the buck, and it shows up as FE.

Jeroen
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Old 30th July 2014, 14:08   #642
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Re: ARTICLE: How to get the maximum Fuel Efficiency

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Originally Posted by Jeroen View Post
Good, so you are doing the best way to calculate FE.
I would suggest to get it hooked up to an OBD analyzer, preferably a car/model specific one and have a competent mechanic make a diagnosis on the live data and or any codes he/she might find. I understand that last time there were no codes. Still, a good OBD analyzer is able to take a wide range of engine performance readings and a good competent mechanic should be able to make a diagnosis, or at least exclude a lot stuff.

I would also suggest not to do anything to the car (e.g. decarbonisation etc) before you have done the OBD code + live data analyser thing.

Black smoke can be an indication of incomplete ignition process. Meaning that not all fuel gets combusted in the most efficient way. Or to put it differntly, under those circumstance you are not getting the correct bang for the buck, and it shows up as FE.

Jeroen


Thank you for your inputs Jeroen. I will bear the same in mind

Cheerio
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Old 30th July 2014, 18:31   #643
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Re: ARTICLE: How to get the maximum Fuel Efficiency

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Originally Posted by Amitabh375 View Post
3. Will also get the engine decarbonised
Please take multiple opinions before decarbonisation. Modern engines should last a long time, 70k km is not too much running. So do decarbonisation if required only.

Last edited by D4D : 30th July 2014 at 18:32.
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Old 31st July 2014, 20:22   #644
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Re: ARTICLE: How to get the maximum Fuel Efficiency

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Originally Posted by GTO View Post
In any turbo-charged car, whether petrol or diesel, the turbo's spooling will always boost fuel efficiency. Research on your car, know when your turbo kicks in, and upshift just above that point. Example : Tata Manza owners would probably get better fuel economy from upshifting at 2,100 rpms vis a vis 1,700 rpm. Plus, its bad news to "lug" a turbo-charged car.

I am no Automobile Engineer but i think what GTO says is correct.

I own a Manza and I have found that at Top Gear the Manza runs at around 2000rpm with speeds of around 80kmh and I have always got phenomenal averages. Obviously in city traffic one cant really floor the gas pedal but over the last year i have noted that maximum FE comes when I drive within this bandwidth.
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Old 31st July 2014, 22:42   #645
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Re: ARTICLE: How to get the maximum Fuel Efficiency

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Originally Posted by shashi63 View Post
I am no Automobile Engineer but i think what GTO says is correct.

I own a Manza and I have found that at Top Gear the Manza runs at around 2000rpm with speeds of around 80kmh and I have always got phenomenal averages. Obviously in city traffic one cant really floor the gas pedal but over the last year i have noted that maximum FE comes when I drive within this bandwidth.
Yes at the point where the turbo spools is where the peak torque is achieved hence lesser strain on the engine and transmission so better FE.

In the MJD / DDiS / Quadrajet engines 80 kmph @ 5th gear is achieved at 1900 RPM; 100 kmph @ 5th gear is achieved at 2300 RPM which I feel are the best cruising speeds hence maximum FE is extracted when on highway drives.

In-gear acceleration from these speeds are easier and quicker as the car is in the turbo range.

Anurag.
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