Go Back   Team-BHP > Team-BHP > Team-BHP Advice > On owning a car


Reply
 
Thread Tools Search this Thread
Old 27th March 2007, 05:36   #76
BHPian
 
Join Date: Dec 2006
Location: Cochin
Posts: 137
Thanked: 5 Times
Default

Here is what I think:

1. If you feel the pressure on the accelerator, you are spending too much fuel. Do that only when needed, like overtaking.

2. If you take the foot away from the accelerator, and you can FEEL the engine braking, you 'had been' going too fast and spending too much fuel

3. If you take the foot away from the accelerator and you can feel the engine jerking (what is the correct term here?), you are going too slow, and you are burning fuel for too long (ie it takes more time to cover the same distance)

Remember, a HAPPY engine is always an FE engine too.
DileepKS is offline   Reply With Quote
Old 27th March 2007, 18:47   #77
Senior - BHPian
 
pjbiju's Avatar
 
Join Date: Apr 2006
Location: Karamattom, Aluva, Kotagiri, Yercaud, Hospet, Indore, Nashik, Pune (now)
Posts: 1,154
Thanked: 420 Times
Default

Simple ways to get more mileage
  • Avoid peak hour traffic, when you can
  • While driving on familiar routes, learn where you need to slow down (turns, bumps, pot hole etc.) and instead of using the breaks to slow down, slow down by stopping acceleration in advance. The more you use your breaks, the less your FE is going to be.
  • Downshift while overtaking, especially from 5th and 4th gears to 3rd gear. This is especially true for petrol cars which have overdrives in the 4th and 5th gears. The roll over time in 3rd gear is less than 4th and 5th gears in most of the cars.
  • Do not try to overtake every vehicle in front of you (in cities that would mean several acceleration-break-acceleration and finally overtaking) especially if the vehicle in front of you is going at a reasonably good speed.
  • Keep a reasonably good distance from the vehicle infront to avoid sudden braking. You may be able to slow down by just taking your foot off the accelerator. (This would also save you from the vehicle behind you from ramming into your vehicle)
  • Switch off your A/C while overtaking - in many cars there is a considerable drop in engine power when the A/C is switched on. Turning them off helps you to accelerate faster.
pjbiju is offline   Reply With Quote
Old 28th March 2007, 05:43   #78
Senior - BHPian
 
mithun's Avatar
 
Join Date: Jan 2006
Location: Cochin
Posts: 1,912
Thanked: 39 Times
Default

Quote:
Originally Posted by akroy
Infact when u r in 5th gear doing higher speeds(say 100kmph) and remove ur foot of the accelerator, ur fuel is cutoff automatically (in MPFI engines) and engine braking mechanism makes sure that you are not out of control...U will achieve some unbelievable FE by the following practice...

say at 100kmph/5th gear u remove ur foot, let engine braking decrease the speed to 70-80kmph then u again put foot on the pedal and increase the speed to 100kmph and remove the foot again....and continue doing this process...
Cent percent folly !!!

I don't think that this trick will ever work and will give more mileage than cruising steadily at 70-80 km/h due to the acceleration & deceleration involved and the high proportion of air drag that needed to be overcame at 100 km/h when compared to 70-80 km/h.

Also the time required for acceleration to 100 km/h will be more than the time needed for the deceleration from 100 km/h to 70-80 km/h.
mithun is offline   Reply With Quote
Old 28th March 2007, 08:49   #79
Senior - BHPian
 
akroy's Avatar
 
Join Date: Feb 2006
Location: San Francisco, CA, USA
Posts: 2,414
Thanked: 25 Times
Default

Quote:
Originally Posted by mithun View Post
Cent percent folly !!!

I don't think that this trick will ever work and will give more mileage than cruising steadily at 70-80 km/h due to the acceleration & deceleration involved and the high proportion of air drag that needed to be overcame at 100 km/h when compared to 70-80 km/h.

Also the time required for acceleration to 100 km/h will be more than the time needed for the deceleration from 100 km/h to 70-80 km/h.
Mithun, Strong statement mate, but you think so but I have tried and tested it...
There is no significant change in airdrag at 80kmph & 100kmph due to the aerodynamic design of car (with windows up)
My statement was of optimization of the FE and at the same time maintain the speeds so that I can cover my distances quickly. (Basically extracting the highest FE and covering the maximum distance)

I agree that u will get the best FE at 60kmph & 5th gear but can u do that in real conditions on a long drive on a highway???? If that is the case, it is better to go in bus which will be shorter in terms of time as well as money !!!

Finally, try it out yourself...I have tried it on all roads and at all speeds, loads and distances and this statement was also based on my experience...

Hope you have understood !!!
Abhi
akroy is offline   Reply With Quote
Old 28th March 2007, 09:59   #80
BHPian
 
Join Date: Feb 2007
Location: Bangalore
Posts: 191
Thanked: Once
Default

You can maximise your fuel efficiency by shifting to the right gear at the right time, but a caveat to that is shifting gears too often is not good either. Shift smoothly, every time you jerk you stress your mechanicals (and your passengers) that much more.

Make sure you dont press the pedal any more than 25% of its full travel at any time, unless your vehicle does not have enough torque as you start off from a lower speed. Get into 'cruise' mode - i.e. 60~70kmph in 5th when you get the opportunity.
wizardofid is offline   Reply With Quote
Old 16th April 2007, 18:51   #81
BHPian
 
Join Date: Jun 2006
Location: Noida
Posts: 30
Thanked: 0 Times
Default

Hi
Is the downsizing of the gear good option during overtaking with efficiency point of view? Recently, during my recent travel from Dehradun to Delhi (fully loaded Petra 1.6), I was forced to downsize when overtaking vehicles at a speed of 80kmph, I was feeling lack of power. I was thinking, I was having problem with fuel or car. But is it because of overdrive? Is that good for efficiency?
Subodh Kumar is offline   Reply With Quote
Old 16th April 2007, 19:19   #82
Senior - BHPian
 
drifter's Avatar
 
Join Date: Sep 2004
Location: Bombay
Posts: 1,466
Thanked: 8 Times
Default

Quote:
Is the downsizing of the gear good option during overtaking with efficiency point of view
Let the fuel economy go to the dogs when overtaking, downshift as necessary when overtaking, its a safety issue.

Drifter
drifter is offline   Reply With Quote
Old 16th April 2007, 20:03   #83
Senior - BHPian
 
zenx's Avatar
 
Join Date: Oct 2004
Location: Bangalore
Posts: 1,057
Thanked: 65 Times
Default

Dunno about the max efficiency, but if you don't want it to dip, don't let me near your car! (I get average to bad efficiency out of all my vehicles - and then they get tested with 10-15% more at the service guys' place - at least the bikes) I don't really drive with a heavy foot all the time, but us the throttle/accelerator to get pretty quick 0-whatever times, shift at high revs, and keep the Honda/Pulsar on the boil
How I envy the 16kmplers....
zenx is offline   Reply With Quote
Old 17th April 2007, 12:41   #84
BHPian
 
Join Date: Mar 2005
Location: MUMBAI
Posts: 89
Thanked: 0 Times
Default

[quote=drifter;414808]Let the fuel economy go to the dogs when overtaking, downshift as necessary when overtaking, its a safety issue.

Well said, it would be very difficult to try and overtake in higher gears especially when you do not have much time.
nik1982 is offline   Reply With Quote
Old 17th April 2007, 15:22   #85
BHPian
 
Join Date: Jun 2006
Location: Noida
Posts: 30
Thanked: 0 Times
Default

I just wanted to know whether lowering one gear below while overtaking at high speeds (say 80-90kmph) is normal or not? Is it felt in other cars also particularly 1600 CC enginer? I am new and was surprised when faced this, I had thought 1600CC car should not face this kind of problem. I agree, safety has to be the most important.
Subodh Kumar is offline   Reply With Quote
Old 17th April 2007, 16:23   #86
Senior - BHPian
 
Bass&Trouble's Avatar
 
Join Date: Mar 2006
Location: Bombay
Posts: 2,737
Thanked: 64 Times
Default

Quote:
Originally Posted by Subodh Kumar View Post
I just wanted to know whether lowering one gear below while overtaking at high speeds (say 80-90kmph) is normal or not? Is it felt in other cars also particularly 1600 CC enginer? I am new and was surprised when faced this, I had thought 1600CC car should not face this kind of problem. I agree, safety has to be the most important.
Deosnt this totally depend only on whethere there is a need to accelerate in order to make the overtake or not? How would it have to anything to do with car/ make/ model/ engine capacity etc?
Bass&Trouble is offline   Reply With Quote
Old 18th April 2007, 13:18   #87
k36
BHPian
 
k36's Avatar
 
Join Date: Dec 2005
Location: Pune
Posts: 131
Thanked: 9 Times
Default

Quote:
Originally Posted by Subodh Kumar View Post
I just wanted to know whether lowering one gear below while overtaking at high speeds (say 80-90kmph) is normal or not? Is it felt in other cars also particularly 1600 CC enginer? I am new and was surprised when faced this, I had thought 1600CC car should not face this kind of problem. I agree, safety has to be the most important.
In all cars, regardless of engine, the highest gear is designed for cruising, keeping FE in mind, and not accelerating. Hence while overtaking you need to shift down.
k36 is offline   Reply With Quote
Old 28th April 2007, 10:56   #88
GTO
Team-BHP Support
 
GTO's Avatar
 
Join Date: Feb 2004
Location: Bombay
Posts: 43,426
Thanked: 61,529 Times
Default

Added the following point to the original article. This has been reported as a very important contributor to fuel efficiency:

Quote:
• The honest petrol pump: Considering the high amount of fuel adulteration and other fuel-industry malpractices, we highly recommend you to choose the right petrol pump. Tampered meters that result in under-filling, misappropriating bills and selling adulterated fuel are some of the most common malpractices. Company-owned filling stations are the best option, though there are some honest privately-owned petrol pumps also. Look around and opt for an honest reputable petrol pump. This alone can account for upto a 10% difference in your fuel efficiency.
GTO is offline   Reply With Quote
Old 28th April 2007, 11:43   #89
BHPian
 
Join Date: Feb 2007
Location: Pune
Posts: 144
Thanked: 0 Times
Default

Carpool !!! That's the mother of all the FE related tips on earth. Suddenly, your 15kmpl car become a 30kmpl one (effectively). Check-out ********.com or commuteeasy.com.
amu1983 is offline   Reply With Quote
Old 14th May 2007, 18:18   #90
BHPian
 
appuchan's Avatar
 
Join Date: Jan 2006
Location: Bangy
Posts: 639
Thanked: 13 Times
Default

Quote:
Originally Posted by akroy View Post
...
There is no significant change in airdrag at 80kmph & 100kmph due to the aerodynamic design of car (with windows up)...
I dont have equipment to try it out. But one thing I can say from Physics is that Air Drag is proportional to the square of the velocity. So if air drag is say 200 N at 80 kmph, at 100 kmph it should be 300+ N. No small amount this. Note that rolling drag is considered as constant across speeds.
appuchan is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Article on how ARAI conducts its fuel-efficiency tests vishnurp99 Technical Stuff 28 3rd May 2016 12:18
Where to get fuel (lid /cap) stickers to Avoid confusion at Fuel Station? kspv Modifications & Accessories 20 18th March 2010 01:06
Swift ZXi Climate control_improve fuel efficiency pranil Technical Stuff 21 13th March 2006 18:16


All times are GMT +5.5. The time now is 19:19.

Copyright 2000 - 2016, Team-BHP.com
Proudly powered by E2E Networks