Most car and motorbike companies provide tested and verified mileage of their car models or motorbike models. Two things you must have observed that they provide two mileage figures- city mileage and highway mileage and second- highway mileage is greater than the city mileage or in other words highway fuel consumption is less than city roads.
As per my observation most people only look at those mileage figures at the time of purchasing the vehicle but afterwards very few pay attention to the actual mileage per unit of fuel consumed by the vehicle. Further most of the people think mileage is an inherent characteristics of a vehicle and only a vehicle mechanic can tinker with it.
The astonishing thing is that I have even seen engineers doing the same thing. Most of my friends are engineers and almost none pays attention to the mileage figure of their vehicle.
But on the other hand, I have seen some handful of guys understanding and finding and tinkering with the mileage of their vehicles. I guess curiosity is the common thing among these guys.
Well until now if you have not measured the mileage of your vehicle, don't worry. As you are reading this article, you are curious enough.
This article is to be read along with,
The power of compounding- 10 ways to improve your bikes mileage
Ok, so let's now come back to our myth- the city mileage and the highway mileage-
Most of the time, my observation is in contradiction with the automakers. My motorbike and car gives less highway mileage than city mileage. And I can safely bet that for most of the people it is the same way.
Now why it is so?
There are two reasons-
1) AIR RESISTANCE-
Now what is this AIR RESISTANCE?
Whenever any object is moving in the stationary air, the air in front of it gets pushed by the object, also there is a vacant space produced behind the object as it moves forward. It is like moving through a densely packed crowd. You have to push the person in front of you away from your path and as you go forward the person occupies the space formed behind you. So you encounter a resistance to go forward. The more speed with which you want to go forward the more resistance you have to encounter. And if you move more than a certain limit you may get beaten up by the persons you are pushing. :-)
The same thing happens with your vehicle. As your speed increases the air resistance increases.
The air resistance quadruples as your speed doubles.
So you burn more and more fuel to overcome this air resistance as you increase your speed.
To reduce this air resistance which is also called air drag most cars are made aerodynamic (i.e. stream lined). So that they have to make less movement in the air. Or in other words they make it easy for the air to move around it.
But still as your speed doubles the air drag quadruples.
To understand the might of the air drag let's see another example-
The air drag is so negligible for us humans that we never give a thought about it while walking or running. It is because normal humans seldom run and even if we run, we can run at the top speed of 15km per hour and we generally walk at 4km per hour. So we just feel a little wind blowing around us when we run and no movement of air while we walk. That is we have to apply very little force to overcome the drag while walking or running. But suppose you are able to run at say 200km per hour then you have to apply the force equal to your weight to overcome the air drag. For example of you with 70kg then you would have to apply 70kg of forward force to overcome the air drag to run at 200km per hour(if you were able to run at that speed with our normal aerodynamics).
Usually we drive slowly in the city traffic as the roads are crowded and the speed limit is also lesser than the highways. Therefore if you are driving in a relaxed manner then you will encounter much lesser air drag, hence lower fuel consumption.
But on the highways you have open roads with higher speed limits, so obviously we drive at higher speeds on the highways. Which increases the fuel wasted on overcoming the air drag.
Now the second reason-
2) ENGINE EFFICIENCY-
The internal combustion engines (i.e. gasoline or diesel engines) fitted in our vehicles are operated in the wide range of RPM. The throttle governs the fuel going in the engine and thereby governing the RPM. While driving the vehicle we are constantly changing the RPM of the vehicle to suit the driving conditions.
But the engines efficiency is highest in a narrow band of RPM. Above this narrow band or below this narrow band the efficiency of the engine decreases drastically. Generally the vehicle operates the most economically when it is in the top gear and the RPM a little above stalling RPM (stalling is when the engine RPM is so low that it can't function smoothly). In such a condition your vehicles engine will be working comfortably and most efficiently.
If you look at the specifications of the engine, they generally provide a maximum torque figure and the RPM at which you get this maximum torque. This is the RPM at which the vehicle operates most efficiently. So in any gear depending on the driving condition of we stick to this RPM then we will get the best fuel economy possible.
But we almost always exceeded this RPM by a huge margin whenever driving on highways. Therefore the engine is working far away from the economic working zone of the engine.
So the result is LOW FUEL ECONOMY.
(The working of an engine is similar to us. For example, though an average person can run at the top speed of 15km per hour, we seldom cross 4km per hour. If we start running, soon our body starts struggling to get enough oxygen, struggling with removing the excess heat generated, struggling with the lactic acid generation in the muscles etc. Same is the case with the automobile engine. As we work great when we are doing things in our comfort zone most of the time, the same is applicable for automobile engine.)
I have tried to make this subject as easy to understand as possible. Hope you are ready to apply and save fuel.
See you soon.. Till then have s nice time..
Sumit
The POWER is when,
You use ODDS,
To get EVEN.
As per my observation most people only look at those mileage figures at the time of purchasing the vehicle but afterwards very few pay attention to the actual mileage per unit of fuel consumed by the vehicle. Further most of the people think mileage is an inherent characteristics of a vehicle and only a vehicle mechanic can tinker with it.
The astonishing thing is that I have even seen engineers doing the same thing. Most of my friends are engineers and almost none pays attention to the mileage figure of their vehicle.
But on the other hand, I have seen some handful of guys understanding and finding and tinkering with the mileage of their vehicles. I guess curiosity is the common thing among these guys.
Well until now if you have not measured the mileage of your vehicle, don't worry. As you are reading this article, you are curious enough.
This article is to be read along with,
The power of compounding- 10 ways to improve your bikes mileage
Ok, so let's now come back to our myth- the city mileage and the highway mileage-
Most of the time, my observation is in contradiction with the automakers. My motorbike and car gives less highway mileage than city mileage. And I can safely bet that for most of the people it is the same way.
Now why it is so?
There are two reasons-
1) AIR RESISTANCE-
Now what is this AIR RESISTANCE?
Whenever any object is moving in the stationary air, the air in front of it gets pushed by the object, also there is a vacant space produced behind the object as it moves forward. It is like moving through a densely packed crowd. You have to push the person in front of you away from your path and as you go forward the person occupies the space formed behind you. So you encounter a resistance to go forward. The more speed with which you want to go forward the more resistance you have to encounter. And if you move more than a certain limit you may get beaten up by the persons you are pushing. :-)
The same thing happens with your vehicle. As your speed increases the air resistance increases.
The air resistance quadruples as your speed doubles.
So you burn more and more fuel to overcome this air resistance as you increase your speed.
To reduce this air resistance which is also called air drag most cars are made aerodynamic (i.e. stream lined). So that they have to make less movement in the air. Or in other words they make it easy for the air to move around it.
But still as your speed doubles the air drag quadruples.
To understand the might of the air drag let's see another example-
The air drag is so negligible for us humans that we never give a thought about it while walking or running. It is because normal humans seldom run and even if we run, we can run at the top speed of 15km per hour and we generally walk at 4km per hour. So we just feel a little wind blowing around us when we run and no movement of air while we walk. That is we have to apply very little force to overcome the drag while walking or running. But suppose you are able to run at say 200km per hour then you have to apply the force equal to your weight to overcome the air drag. For example of you with 70kg then you would have to apply 70kg of forward force to overcome the air drag to run at 200km per hour(if you were able to run at that speed with our normal aerodynamics).
Usually we drive slowly in the city traffic as the roads are crowded and the speed limit is also lesser than the highways. Therefore if you are driving in a relaxed manner then you will encounter much lesser air drag, hence lower fuel consumption.
But on the highways you have open roads with higher speed limits, so obviously we drive at higher speeds on the highways. Which increases the fuel wasted on overcoming the air drag.
Now the second reason-
2) ENGINE EFFICIENCY-
The internal combustion engines (i.e. gasoline or diesel engines) fitted in our vehicles are operated in the wide range of RPM. The throttle governs the fuel going in the engine and thereby governing the RPM. While driving the vehicle we are constantly changing the RPM of the vehicle to suit the driving conditions.
But the engines efficiency is highest in a narrow band of RPM. Above this narrow band or below this narrow band the efficiency of the engine decreases drastically. Generally the vehicle operates the most economically when it is in the top gear and the RPM a little above stalling RPM (stalling is when the engine RPM is so low that it can't function smoothly). In such a condition your vehicles engine will be working comfortably and most efficiently.
If you look at the specifications of the engine, they generally provide a maximum torque figure and the RPM at which you get this maximum torque. This is the RPM at which the vehicle operates most efficiently. So in any gear depending on the driving condition of we stick to this RPM then we will get the best fuel economy possible.
But we almost always exceeded this RPM by a huge margin whenever driving on highways. Therefore the engine is working far away from the economic working zone of the engine.
So the result is LOW FUEL ECONOMY.
(The working of an engine is similar to us. For example, though an average person can run at the top speed of 15km per hour, we seldom cross 4km per hour. If we start running, soon our body starts struggling to get enough oxygen, struggling with removing the excess heat generated, struggling with the lactic acid generation in the muscles etc. Same is the case with the automobile engine. As we work great when we are doing things in our comfort zone most of the time, the same is applicable for automobile engine.)
I have tried to make this subject as easy to understand as possible. Hope you are ready to apply and save fuel.
See you soon.. Till then have s nice time..
Sumit
The POWER is when,
You use ODDS,
To get EVEN.
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