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Old 1st June 2007, 13:02   #1
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Cool Step on the metal if you want to save CO2

Hi everybody ,
Have a look at this article.What's team-bhp stand on it.

" A British automotive engineering consultancy claims to have unearthed proof that putting your foot down hard on the accelerator can actually be more fuel efficient than driving more conservatively. Dr Steve Cousins from Axon Automotive told the Sunday Times newspaper that "the key to saving fuel is to accelerate hard until the engine reaches 2000rpm, move up a gear, then put your foot down until you reach 2000rpm again." It's all to do with internal friction, he apparently said, explaining that the engine works at its most efficient when the accelerator is pressed, although the fuel economy benefits do apparently start to diminish above 2000rpm. The Sunday Times notes that tests carried out in a Citroen C1 proved Dr Cousins' theory to be true, and that his driving technique was 8.5% more fuel efficient than following the government's 'eco-safe driving' advice, which encourages only light pressing of the accelerator pedal. At the recent 'Sexy Green Car Show' at The Eden Project in Cornwall, Axon Automotive encouraged people to drive in the most fuel efficient way with a rev-counter which indicates the best time to change gear in order to save on fuel."

The url is News Archive: All the latest up to date news on the car parts industry found here
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Old 1st June 2007, 13:21   #2
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Very interesting study. Our government now has a very real reason to provide high speed roads - all in the name of saving Mother Earth
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Old 1st June 2007, 15:17   #3
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Quote:
Originally Posted by Ravi Yadav View Post
accelerate hard until the engine reaches 2000rpm, move up a gear, then put your foot down until you reach 2000rpm again"
is this idea for diesel engines?
what's meant by accelerate hard until 2000 rpm?

there are many here whose cars can hit thrice that rpm if accelerated 'hard'. but then those cars and fuel efficiency cant even be the strangest bedfellows either.
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Old 1st June 2007, 15:23   #4
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It means reach 2000 rpm as soon as possible. Since the engine is most fuel efficient in a given rpm. (would it be same for all engines ?). If only scanguage would work, it would be easy to find the right conditions for more efficiency.
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Old 1st June 2007, 16:19   #5
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The RPM at which engine generates max. torque is also when it is most fuel efficient. Learnt this while studying Mechanical Engineering at the engine laboratory almost 14 yrs ago. You would know from the technical specifications for your engine which is available.

eg. max power xx BHP @ yy rpm & max torque xx Nm @ yy rpm
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Old 1st June 2007, 16:22   #6
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Its common sense.
If you floor the accelerator at 50kmph in fifth gear to accelerate to 100, you will burn much more fuel than say, accelerate to 80 in third, then to 100 in 4th and then shift to 5th.
In acceleration its always best not to floor.
Flooring the accelerator will allow maximum about of fuel into the engine.
I always accelerate with limited pressing of the pedal, and if I want to accelerate fast I shift to a lower gear, reach my required speed and then upshift.
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Old 1st June 2007, 17:02   #7
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Quote:
Originally Posted by tsk1979 View Post
Its common sense.
I always accelerate with limited pressing of the pedal, and if I want to accelerate fast I shift to a lower gear, reach my required speed and then upshift.
In fact that is when you accelerate in the cruckator... if you floor on 5th at 100 you just about pull or maybe just about drag heaving like an asthma patient
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Old 1st June 2007, 17:07   #8
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Quote:
Originally Posted by Zappo View Post
In fact that is when you accelerate in the cruckator... if you floor on 5th at 100 you just about pull or maybe just about drag heaving like an asthma patient
Zappo da, What is Cruckator, Pardon me for ignorance...
BTW, I dont think that is a good practice....It is clearly written in the booklet of Alto (To achieve higher FE, Shift to the upper gears at this speeds, eg 5th in 40-45kmph, ofcourse u r on straight road and not incline and AC off)

Abhi
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Old 1st June 2007, 17:18   #9
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i thinkmost people are getting this wrong! @akroy dude the study says to reach the required RPM faster! so you are changing gears at the same RPM say 2k , but he says you should floor it to reach 2k instead of using a light foot! so you'd be shifting at the same speed just getting to it faster!!

doesn't seem like it would work ! but you know im sure most of us wouldnt have driven like that! because if you are thinking FE you drive with a light foot and if you are trying to accelerate to speed up you change much later than 2k rpm!
i dont think it'll help in our city stop and go trafic anyways maybe someone can try it on the highways!!
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Old 2nd June 2007, 12:55   #10
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Hello. Trying this way. Only hard thing is.. too frequent gear changes. Like i shift to 1st from a stop and move off quickly to 2k rpm. It accelerates very rapidly and it would be like every 2-3 seconds a gearshift would be done until the top gear. But i think this is true because the engine always performs at its best at its optimum rpm and returns good mileage too. To use this way, I'd prefer a triptronic A/T.

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Old 2nd June 2007, 22:16   #11
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Quote:
Originally Posted by risga View Post
The RPM at which engine generates max. torque is also when it is most fuel efficient. Learnt this while studying Mechanical Engineering at the engine laboratory almost 14 yrs ago. You would know from the technical specifications for your engine which is available.

eg. max power xx BHP @ yy rpm & max torque xx Nm @ yy rpm

Is this practical? I mean, those lab experiments were on a stationary engine with no or very little load. But if your car runs at 100KMPH in final gear at peak torque range, isnt the wind resistance enough to bring down your fuel efficiency?
me thinks driving at 60 in final gear will save more fuel if peak torque in final gear takes you to 100 or so..
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Old 2nd June 2007, 23:14   #12
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^ Wow! I dint know this bit that the engine is most efficient at the rpm where it offers max torque..

In that case then I'd like to have an engine that offers max torque at 5k rpm and be efficient too..

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Old 3rd June 2007, 17:33   #13
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Very interesting and good debatable article.
The key word here is HARD and what is meant by it.

From what I understand it means press your accelarator more than suggested for economy driving till car reaches required rpm i.e. 2000
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