ARTICLE: How to get the maximum Fuel Efficiency

[pmbabu]

I have query about the idling part yet.

In Bangalore, at traffic signals, I usually wait 2-3 minutes. Idling for 3 minutes or igniting the engine on (after switching it off in a signal), which one would cost more fuel?

[rks]

Originally Posted by GTO

DRIVING STYLE

• Choosing the right gear: Being in a higher gear at too low a speed, or in a lower gear at a very high speed increase your fuel consumption. It is important to shift up as “early” as possible without straining the engine. For most cars, the ideal shift point would be anywhere between 1500 – 2000 rpm.

• Maintain a constant speed: Varying speeds do not make the car as efficient as a constant speed will. Especially when out on the open road, try to maintain a consistent rate of travel.

• The Optimum speed: Aerodynamic resistance increases exponentially with speed. For e.g. at speeds over a 100 km/h, your car will consume a lot more fuel than at 80 – 90 km/h. Keep within this limit to maximize the FE of your car.

I would like to add a couple of points to this well-thought-out list. All the three points quoted above are on target. Related to these points, I would like to add:

-- For maximum fuel economy, the optimal speed should be slightly above the minimum at which you can shift to highest possible gear. For example, in city driving on level terrain, I would say that you should try to maintain something like 45-60 kmph in a Santro, since you can shift to fifth at 45. If you drive around in fourth gear at 40 kmph, it would be less economical than driving at 45-60 in fifth. The idea is to stay at these speeds steadily for as long as possible in fifth gear. So if you don't like to overtake slow-moving vehicles like lorries or autos, then you may be driving around in third gear a lot of the time and your FE will suffer. But on the other hand, too much acceleration and braking is also bad, as pointed out.

-- Turn off AC if you don't need it; keep windows rolled up with only the fan on if the weather is cool enough.

[Gordon]

Air-Conditioning: The A/C of your car can make your car consume more fuel. So turn it off when not essential. Use the blower instead.

[anubis]

Really useful to a lot of newbies who are pedal happy !!!!!!!!!!! Great work GTO. Keep it up

[goldsun]

Nice summarised tips to increase FE. Many of these tips when adhered to will also increase the driving safety.

[GTO]

All this coming from someone who used to be revv-happy and for whom FE was the least important factor in selecting a car (atleast that is what the tbhp archives indicate).

No ways, I still couldnt care less about fuel efficiency. But I am obviously part of a very small minority and hence...this article.

Thanks for the suggestions guys. Once they add up, I will add them to the original article.

[supremeBaleno]

Originally Posted by pmbabu

I have query about the idling part yet. In Bangalore, at traffic signals, I usually wait 2-3 minutes. Idling for 3 minutes or igniting the engine on (after switching it off in a signal), which one would cost more fuel?

A PCRA brochure with me that was printed some 15-20 years ago (when engines were not so intelligent / sophisticated) indicated that if you are going to wait for more than 2 mins, it is better to switch off. Recent documents indicated that if idling for 1 min or more, it is better to switch off, and this is what I had been following till yesterday.

However, while googling on this yesterday, I found that for the current generation cars, this limit has come down to as low as 10secs. So, anything more than 10 secs and you can switch off the engine and the fuel saved is more than what is used for restarting the engine.

Also, the frequent starts due to this do not have much of an impact on the starter motor etc, as per the studies. Apart from saving fuel, this practice also reduces pollution and helps save a fast diminishing non-renewable resource.

Originally Posted by GTO

No ways, I still couldnt care less about fuel efficiency. But I am obviously part of a very small minority and hence...this article.

I know. And that was mentioned in jest.
Anyway, a commendable effort in the right direction.

[magiceye]

****I found that for the current generation cars, this limit has come down to as low as 10secs. So, anything more than 10 secs and you can switch off the engine and the fuel saved is more than what is used for restarting the engine. ****

Does this apply to all cars irrespective of whether they are petrol/diesel/turbo?

[supremeBaleno]

Originally Posted by magiceye

Does this apply to all cars irrespective of whether they are petrol/diesel/turbo?

I did not see any specific reference to petrol. And diesel engine technology is also becoming better by the day, just like petrol. So I am guessing that it applies for diesel too. But then I could be wrong also, as I have only a very limited/basic idea about diesel technology.

[kphilip]

GTO, that was an awesome piece of information which should be made to practice..

[sportive_guy30]

Thanks GTO, very well explained.

Finding right, reliable fuel station is one of the most important factor in fuel efficiency. If you get right quantity (if meter is not tampered) and right quality (not adulterated, mixed with naphtha/kerosene etc.) then certainly pure petrol will help us not only in fuel efficiency but also increase life of the car engine

Try to locate COCO (company owned company operated) fuel stations or get tips from autowallahs.

Note from Team-BHP Support : Please do NOT use other word processing softwares. The formating is not compatible with our forum software.

[esteem_lover]

very informative. car pooling is one that is such a nice thing to do, but still has not caught up here in india, at least not in chennai. there is a family in my colony whose children get driven to school daily in their ikon. my son goes to the same school by van & sometimes i drop him, if time permits. when i suggested that we pool with my car one day & theirs the next, they simply did not want to. after that i often see them hurriedly packing off their kids in an auto when their driver fails to turn up. still they have not learnt their lesson. how stupid !!

[ram_hyundai]

hi,
One important point to note here is that -intelligent use of air con.see the point is that you should be comfortable ,not that your a chicken in a freezer which could get useless if its out of it.when the car ambient temperature is comfortable switch it off and let the blower be left as it is .and you know when the temperature sores up and then switch it on.by this way if your travelling say 100 kms you might be using the a/c for say 60 kms in effect which can save you a lot . gto it was a comprehensive and informative piece you layed down here.

cool journeys guys not freezing journies
ram

[Surprise]

I do car-pooling with one of my friend who resides next street & we both work for the same organization.

The very very important thing that needs to be followed is maintaining punctuality. If you make the other guy wait for 10-15 mins after you are ready otherwise vice versa will make the individual frustrated. Otherwise people involved in pooling needs to get prepared for 10-15 mins delay. If you start fuming about the delay, Iam sure it is not going to succeed.

By this way my petrol bills are cut half at the cost of driving pleasure.

PS: I do car pooling not to save money on it, but to have a companion in the front seat for chatting

[sandeep108]

Originally Posted by magiceye

****I found that for the current generation cars, this limit has come down to as low as 10secs. So, anything more than 10 secs and you can switch off the engine and the fuel saved is more than what is used for restarting the engine. ****

Does this apply to all cars irrespective of whether they are petrol/diesel/turbo?

In mumbai / bangalore traffic, I see no point really in switching car off for 10s, on for 20s, maybe 3 times in 2 mintues. The countdown timers help, but again AC stops so cooling down has to start all over again.