Tips To Improve Your Car’s Fuel Efficiency


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how to get max fuel efficiency,Tips!!! & Reasons

Hi , TAIgers
This this another yet useful thread by your Prasanth Krishna ,
Enjoy.

NOTE: Thread may be longer than you think, better have a cup of coffee and relax yourself,
If you are in an hurry, please take a time later to read, because this is going to be more deeper to understand and could save you 30% of your fuel bills.

As the fuel prices are increasing more aggressively these days, our cars consume those without knowing the prices, so better you train them to get less fuel for attaining more distance
Keep in mind, every thing about max fuel efficiency is not only on saving money, its all about how greener you are in roads .
Its all about KEEPING THE MOMENTUM OF YOUR CAR,TO COVER DISTANCE
If you are a beginner go with basic things as below, else you are a pro!!
Go for pro reader section after this section.
FOR BEGINNERS
Whether you drive a tiny car or a three-ton SUV, chances are you can squeeze a bit more distance out of each gallon of fuel -- and at today's gas prices, an improvement of just one or two miles per gallon can really add up. These ten fuel saving tips have served me well over the years, and they can help you improve your car's fuel economy and take some of the sting out of high gas prices. Most of these tips will give you a very slight increase in kmpl -- but use several together and the gas mileage improvements will really add up.

1. GO Slow
One of the best ways to save gas is to simply reduce your speed. As speed increases, fuel economy decreases exponentially. If you are one of the "ten-over on the freeway" set, try driving the speed limit for a few days. You'll save a lot of fuel and your travel times won't be much longer.

2. tire pressure
Under-inflated tires are one of the most commonly ignored causes of crummy KMPL. Tires lose air due to time (about 1 psi per month) and temperature (1 psi for every 10 degree drop). Under-inflated tires have more rolling resistance, which means your engine has to work harder to keep your car moving. Buy a reliable tire gauge and check your tires at least once a month. Be sure to check them when they are cold, since driving the car warms up the tires (and the air inside them), which increases pressure and gives a falsely high reading. Use the inflation pressures shown in the owner's manual or on the data plate in the driver's door jamb.

3. Air filter
A dirty air filter restricts the flow of air into the engine, which harms performance and economy. Air filters are easy to check and change: See your owner's manual for instructions. Remove the filter and hold it up to the sun; if you can't see light coming through it, you need a new one. Consider a K&N or similar "permanent" filter which is cleaned rather than changed. They provide better airflow than throw-away paper filters and they're better for the environment.
4. Accelerate with care
Jack-rabbit starts are an obvious fuel-waster -- but that doesn't mean you should crawl away from every light. If you drive an automatic, accelerate moderately so the transmission can shift up into the higher gears. Stick-shifters should shift early to keep the revs down, but don't lug the engine; downshift if you need to accelerate. Keep an eye well down the road for potential slowdowns. If you accelerate to speed then have to brake right away, that's wasted fuel.

5. Hang with the trucks
Ever notice how, in bad traffic jams, cars seem to constantly speed up and slow down, while trucks tend to roll along at the same leisurely pace? A constant speed keeps shifting to a minimum ,important to big-rig drivers who have to wrangle with those ten-speed truck transmissions ,but it also aids economy, as it takes much more fuel to get a vehicle moving than it does to keep it moving. Rolling with the big rigs saves fuel (and aggravation).

6. Get back to nature
Consider shutting off the air conditioner, opening the windows and enjoying the breeze. It may be a tad warmer, but at lower speeds you'll save fuel. That said, at highway speeds the A/C may be more efficient than the wind resistance from open windows and sunroof. If I'm going someplace where arriving sweaty and smelly could be a problem, I bring an extra shirt and leave early so I'll have time for a quick change.

7.Use stock tyre sizes
New wheels and tires may look cool, and they can certainly improve handling. But if they are wider than the stock tires, they'll create more rolling resistance and decrease fuel economy. If you upgrade your wheels and tires, keep the old ones. I have fancy sport rims and aggressive tires on my own car, but I keep the stock wheels with a good narrower-tread performance tire in the garage. For long road trips, the stock wheels give a smoother ride and better economy.
8. Clean out your car
If you're the type who takes a leisurely attitude towards car cleanliness -- and I definitely fall into that category -- periodically go through your car and see what can be tossed out or brought into the house. It doesn't take much to acquire an extra 20 to 30 kgs. of stuff, and the more weight your car has to lug around, the more fuel it burns.

9. Downsize or hybridize
If you're shopping for a new car, it's time to re-evaluate how much car you really need. Smaller cars are inherently more fuel-efficient, and today's small cars are safer and roomier than ever. And if you've never considered a diesel, maybe it's time .

10.use assistive devices
If your car is a ob2 complaint device, you can buy a Bluetooth OBD2 connector(rs.500 to 1000 Rs.),to pair with your smart phone,these apps communicate with your cars computer and shares information like speed,rpm,fuel pressure,breaking,acceleration,engine load,etc.so you can feel free about driving,where these devices assist you to the max.use torque pro app,and many apps will suggest you to shift up or low according to speed and momentum of car, these are not costly products, but will save you lot of fuel.(a must have for all cars.
 
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Re: how to get max fuel efficiency,Tips!!! & Reasons

FOR PRO USERS!!

The Ideal law.
{
All engines in IDEAL condition must cover a same unit distance for unit of fuel
Ie: energy produced=work done(conditions apply)
}

Conditions are:
1)car must already be running in its average speed
2) you are driving in vaccum(no wind ressistance)
3)all moving parts are 100% lubricated
4)no variation in throttle
5)same O2 level in intake
6)no wear in parts
7)air filter is not present (must be breathing 100% pure air)
8)all energy produced is converted as distance.
9)no load variation
10)same gear ratio (only one gear, taller one, because car is already running in its average speed)
So these conditions are not practically possible
Main reasons why all cars differ in its fuel efficiency figures
• They have different engine sizes
• They have different parts amd shapes,(ac compressor,alternator,passenger,tyre size,weight,wind ressistance……… etc.)
• They have different gear ratios and acceleration graphs
• They have different air intake and injector levels
Etc….

Things you need to understand before getting max fuel efficiency
There is only 20% error due to vehicle, rest is from us driving the vehicle.
So there are infinite factors affecting cars mileage??? Lets brake down to few important factors,
Cars have different torque and power band at varying rpm, also they have different gear ratios, so what you need to do is drive in higher gear as possible without loading your engine,
Every engines job is to take air and fuel into cylinders and make rotational energy converted to tyres
So let engine do its job, so don’t jump on accelerator and expect car to have amazing acceleration, you need efficiency rather than speed.
Say if you are in a signal, say 50s left, first thing you need to do is switch of engine, if you think car will suck fuel if u start engine over again then you are wrong, it only consumes 10s of idling fuel, so if signal time is 10s, you don’t need to switch of engines.
Now signal is open and what you do??
Switch to first and move?? Yes, but not longer ,all cars have shorter first gears ,so switching to second gear within seconds is useful to gain 2.3% of fuel
Now don’t rev more!! Only limit your revs to 30%-50%, depending on your need,
In second and third gear be soft in throttle, many mistakes in feather throttling and not throttling at all,All you need to do is linearly accelerate to your max efficiency speed level, and maintain your momentum, cars have a specific rpm to get max fuel efficiency, but common thing is its not over 30% of rpm,cars have specific rpm levels with each gears for max fuel efficiency,Also you need to consider that limiting revs,is not the factor, you need to keep the momentum of car,now you are in the efficient momentum, then all you need to do is maintain those momentum,linear throttling, helps save up to 25% of fuel efficiency.
Say if your car has efficient RPM of 2000rpm, then let’s assume these factors,
Gear speeds:
1st = 10kmph
2nd =25kmph
3rd =35kmph
4th =40kmpl
5th =50kmpl
So you are attaining different speeds in different gears with same amount of fuel used!!!
Now you understand the concept??? Covering more distance for same amount of fuel,These things are the main factors reducing fuel effeciency,so you need to do is travel in higher gear as possibe
Going fast is so tempting. Not only do we do it to keep up with the flow of traffic, but if we can save even five minutes, it seems worth it. But if you're on the highway, driving 100 kmph per hour instead of 120 kmph will save you 2-4 kms per liter over the duration of your trip.
Windows up. Again, this is tough, especially on pleasant days. But having the windows down creates aerodynamic drag that causes an engine to work harder. On the highway, this can decrease fuel economy by up to 10 percent.
Aggressive driving (speeding, rapid acceleration and braking) wastes gas. It can lower your gas mileage by 33% at highway speeds and by 5% around town.1 Sensible driving is also safer for you and others, so you may save more than gas money.
Avoid keeping unnecessary items in your vehicle, especially heavy ones. An extra 100 pounds in your vehicle could reduce your MPG by up to 2%. The reduction is based on the percentage of extra weight relative to the vehicle's weight and affects smaller vehicles more than larger ones.
Idling can use a half liter of fuel per hour, depending on engine size and air conditioner (AC) use. Turn off your engine when your vehicle is parked. It only takes a few seconds worth of fuel to restart your vehicle. Turning your engine on and off excessively, however, may increase starter wear.
Using cruise control on the highway helps you maintain a constant speed and, in most cases, will save gas.
When you use overdrive gearing, your car's engine speed goes down. This saves gas and reduces engine wear.
Role

Mechanical problems
• If cars piston seals are worn out will extremely reduce economy, also will burn engine oil with fuel and will destroy engine soon
• Tighten up the cam drive belt, so all valve timings and ignition timing will work in a flow to maximise efficiency
• Worn out clutch plate, will drastically reduce FE,so change if any issues are there.
• Check compression pressure in cylinder for any leak in gaskets and piston rings
• Do a dyno test ,to make sure you are with stocks performance curves
Effeciency formula:
road load power = av + bv² + cv³
The letter ‘v’ represents the velocity of the car, and the letters a, b and crepresent three different constants:
The ‘a’ component comes mostly from the rolling resistance of the tires, and friction in the car's components, like drag from the brake pads, or friction in the wheel bearings.
The’ b ‘component also comes from friction in components, and from the rolling resistance in the tires. But it also comes from the power used by the various pumps in the car.
The’ c’ component comes mostly from things that affect aerodynamic drag like the frontal area, drag coefficient and density of the air.
These constants will be different for every car. But the bottom line is, if you double your speed, this equation says that you will increase the power required by much more than double. A hypothetical medium sized SUV that requires 20 horsepower at 50 mph might require 100 horsepower at 100 mph

Efficiency of an Engine
In effect the efficiency of the engine is improving. It uses a fixed amount of fuel to power itself and the accessories, and a variable amount of fuel depending on the power required to keep the car going at a given speed. So in terms of fuel used per mile, the faster the car goes, the better use we make of that fixed amount of fuel required.
This trend continues to a point. Eventually, that road load curve catches up with us. Once the speed gets up into the 40 mph range each 1 mph increase in speed represents a significant increase in power required. Eventually, the power required increases more than the efficiency of the engine improves. At this point the mileage starts dropping. Let's plug some speeds into our equation and see how a 1 mph increase from 2 to 3 mph compares with a 1 mph increase from 50 to 51 mph. To make things easy we'll assume a, b and c are all equal to 1.

Speed Equation Result
3 mph 3+3²+3³ 39
2 mph 2+2²+2³ 14
Power Increase 25
51 mph 51+51²+51³ 135,303
50 mph 50+50²+50³ 127,550
Power Increase 7,753

You can see that the increase in power required to go from 50 to 51 mph is much greater than to go from 2 to 3 mph.
So, for most cars, the "sweet spot" on the speedometer is in the range of 40-60 mph. Cars with a higher road load will reach the sweet spot at a lower speed. Some of the main factors that determine the road load of the car are:
• Coefficient of drag. This is an indicator of how aerodynamic a car is due only to its shape. The most aerodynamic cars today have a drag coefficient that is about half that of some pickups and SUVs.
• Frontal area. This depends mostly on the size of the car. Big SUVs have more than double the frontal area of some small cars.
• Weight. This affects the amount of drag the tires put on the car. Big SUVs can weigh two to three times what the smallest cars weigh.
In general, smaller, lighter, more aerodynamic cars will get their best mileage at higher speeds. Bigger, heavier, less aerodynamic vehicles will get their best mileage at lower speeds.
If you drive your car in the "sweet spot" you will get the best possible mileage for that car. If you go faster or slower, the mileage will get worse, but the closer you drive to the sweet spot the better mileage you will get.

FINAL TIPS
• ACCELERATE LESS
• BRAKE AHEAD
• KEEP STEADY SPEEDS
• CHECK TYRE PRESSURE,AND AIR FILTER
• CLOSE WINDOWS
• DRIVE IN ECONOMY SPEEDS ALWAYS
• KEEP YOUR CAR IN GOOD CONDITION
• KEEP UNWANTED WEIGHTS OUT OF CAR
• KEEP STOCK TYRE SIZE TO REDUCE ROLLING RESISTANCE
• USE OBD ADAPTER FOR ASSISTED DRIVING


Happy miles a head!!!
Make sure to fasten your seat belts!
 
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Re: how to get max fuel efficiency,Tips!!! & Reasons

Excellent write up stingray91 Last weekend I did a Pune Nasik trip which is 225 kms one side in my Zen 2005 CNG model I had constantly driven on 60 kmph as the road is a single lane road completly and mostly crowded with 5 ghats in between to cross. Speeding the vehicle results in braking as due to single lane you cannot maintain desired speed. While going since it was moring time I did not use AC but my windows up but slightly open to pass air as I was travelling alone. While coming I started the journey at 2 pm with family wife and 2 kids, since it was heavy summer I had to travel with full AC on for 225 Kms the fan speed was 2. Here is my fuel consumption expenditure

Distance Tavelled : 450
Gas used : 10.25 kms
Gas cost per Kg : Rs 50
Mileage per kg : 43.90
Trip cost : Rs 512.50

Advantages

1) I saved alot on fuel the same trip cost me Rs 2000 in a petrol vehicle.
2) Less pollution as CNG is a green fuel.
3) Some $ saved for the country as CNG is produced in the country ( Feels good as you are contributing something towards Nation as I am not using perrol or Diesel ).

Some points I strictly follow

1) Regualr service at every 5000 kms
2) Check tyre pressure before every trip
3) Repalce the air filter at every service ( I know it can be cleaned but replacment cost me Rs 200 but helps pass clean air to engine and help engine health nice)
4) People say CNG kills the engine performance but I will say since gas takes times to ignite pick up is very less also engine vibrations are more I have driven my car on CNG for 40,000 kms but have really not faced any issue and current condition of the engine is fit for clocking more 2,00,000 as per my service center guys
 
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Re: how to get max fuel efficiency,Tips!!! & Reasons

Hello, Stingray91,

A very well written post of the day, I should say. Thanks for the in-depth write-up, covering every aspect to be looked at to get maximum fuel efficiency.

NOTE: Thread may be longer than you think, better have a cup of coffee and relax yourself, If you are in an hurry, please take a time later to read, because this is going to be more deeper to understand and could save you 30% of your fuel bills.
Saw your post this evening, and read it fully now.

I believe, knowingly or unknowingly, I follow some of these tips and tricks and observed couple of times that actually I am getting better fuel efficiency. Few of my long drives gave me around 23-25 KMPL mileage.

Good thread and nice replies, hope to see some more from experts.

Peace.
 
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Amit, Can you see stomach burning (just in lighter side buddy) 43.9 km per KG. man. Rs.1.13 per KM. That is amazing man.

Just for info am asking what would be the FE if you are traveling in 80 KM/h Speed?

i think CNG is best while comparing to LPG. I would have max traveled for 100 KMs for that fuel if it is city. If it is hight max 120 KM. Really amazing.

Prashant, Wonderful tips buddy. Even though we follow certain things there were some new tips also. Thank you.
 
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Re: how to get max fuel efficiency,Tips!!! & Reasons

Hi , TAIgers

3. Air filter
A dirty air filter restricts the flow of air into the engine, which harms performance and economy. Air filters are easy to check and change: See your owner's manual for instructions. Remove the filter and hold it up to the sun; if you can't see light coming through it, you need a new one. .

10.use assistive devices
If your car is a ob2 complaint device
Is it safe to carry out instruction no.3 noted above without taking help of a mechanic? It appears that it can be done by self. I have to check mannual.
Pl explain the term ob2 in point no.10.
 
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Re: how to get max fuel efficiency,Tips!!! & Reasons

Is it safe to carry out instruction no.3 noted above without taking help of a mechanic? It appears that it can be done by self. I have to check mannual.
Pl explain the term ob2 in point no.10.
Yes its absolutely safe to check the air filter, nothing wrong in it. Also if its dirty you can clean it just by tapping the filter. If its really dirty new one is needee.

OB2 is not for all cars. Its only for obd2 cars. Its a latest communication protocol designed to communicate with the car ecu with standardized languages. Say if any company produces the car in obd2,even a local mechanic can connect to the cars Ecu and check the errors and clear them, also he can get real-time values of all the sensors and actuators inside. Its very advanced.
So buying obd2 connector is not a issue, and it will not harm cars ecu. Its a communication devices, where the phone software does the job.
 
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Re: how to get max fuel efficiency,Tips!!! & Reasons

Yes its absolutely safe to check the air filter, nothing wrong in it. Also if its dirty you can clean it just by tapping the filter. If its really dirty new one is needee.

OB2 is not for all cars. Its only for obd2 cars. Its a latest communication protocol designed to communicate with the car ecu with standardized languages. Say if any company produces the car in obd2,even a local mechanic can connect to the cars Ecu and check the errors and clear them, also he can get real-time values of all the sensors and actuators inside. Its very advanced.
So buying obd2 connector is not a issue, and it will not harm cars ecu. Its a communication devices, where the phone software does the job.
Prashanth, How do we know whether our car is OBD2 connectable?
 
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Re: Tips To Improve Your Car’s Fuel Efficiency

Amit, Can you see stomach burning (just in lighter side buddy) 43.9 km per KG. man. Rs.1.13 per KM. That is amazing man.
Sethu Sir that is the only reason I am sticking with current car and not changeing the car and stopping me from getting a new XUV or a bolero.
Just for info am asking what would be the FE if you are traveling in 80 KM/h Speed?
On first week of May I did a Pune - Dandeli (Belgaum) trip on that trip I was travelling at a speed of 80 Kmph I got a mileage of 32 km per Kg. For my car its simple the less you press the accelarator more you fetch the mileage.
i think CNG is best while comparing to LPG. I would have max traveled for 100 KMs for that fuel if it is city. If it is hight max 120 KM. Really amazing.
Yes Sir density of CNG is more as Compared to LPG and so the heating point of CNG is around 500 degrees celcius that is reason combustion time is more for CNG as compared to LPG and hence mileage is more for CNG
 

bhvm

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Re: Tips To Improve Your Car’s Fuel Efficiency

Very nice guide and I have one wacky tip!

Choose a good road! I've seen folks go into village/side roads just to avoid 4-lane TOLL TAX. In the Long run, I think Paying toll is beneficial considering the safety, Fuel efficiency and less wear of your vehicle.

What say folks?
 
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@Stingray:

I agree on most of the points except the gear-speed combo in post no. #92

It all depends on the carburetor/injector setting of your vehicle and if you are driving in dense range of the same then you will end up getting a fuel guzzeler out of your vehicle. Try the same in Honda City and you will understand what I mean.

IMO, for getting better FE, it's better if one follows the engine RPM instead of vehicle speed.
 
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Ehh, I have seen cars delivering 13-14 kpl at 50 kph and 18 kph when being driven at 80 kph. This shows that engine speeds actually matters far more than the wheel speed/vehicle speed. Petrol engines are specially tuned(I mean carburetor or EU tuning) to get fuel rich air supply in lower and top end rev range to provide better starting torque and pulling at high speeds while the mid range(say 2000-4500) is having leaner air to fuel ratio(AFR) as it requires just enough torque to keep the vehicle moving.

Driving in this 'leaner' range will always get you better FE - so simple it is.
 
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Re: Tips To Improve Your Car’s Fuel Efficiency

my uncle has been a state bus driver for over more than 25 years. he took my safari for a to attend a marriage in kannur. he recorded a mileage of 17.4 without ac and 15.8 with ac.

these figures are with 5 people on board and loads of luggage. he says you have to talk to the engine.

in ghat sections with ac he got a mileage of 11.4 and without ac 12.8 kmpl
 
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Increasing fuel efficiency for Toyota Fortuner - Any recommendations Dieseltronics ??

Hi,

Recently bought a Toyota Fortuner.

1. Wanted to figure out how to increase the fuel efficiency for Toyota Fortuner. You know the reason.. Fortuner needs more money per month than my self to survive & operate [;)]

2. Please provide me suggestions
(a) Driving habits that would aid higher fuel efficiency, and
(b) Any add-on devices like Dieseltronics or other, which would help to increase the fuel efficiency

Thanks
Vijay
 

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