To Save Fuel
If we choose a vehicle, performance factors such as power, torque, maximum speed, etc are important factors to be considered for decision making, but maintenance and operation cost of the vehicle is also very important factor in view point of TCO (Total Cost of Ownership). For maintenance we need to consider consumables such as, engine oil, tire, air-cleaner filter, spark plug and so on, but all these cost is negligible if we compare the cost of fuel for vehicle operation.
If a vehicle is introduced in the market, the basic fuel economy characteristic is already decided during the design phase, therefore we cannot change this basics after the car is assembled. The only thing we can do is to learn a driving behavior which can keep the fuel consumption relative low. The fuel is consumed to make the traction force which is necessary to win resistance force. This means if the resistance force can be reduced, then the fuel can be saved. Then, how can we reduce the resistance forces ?
As written in the vehicle performance chapter, there are four kinds of resistance forces.
- Aero-dynamic Resistance
- Rolling Resistance
- Acceleration Drag
- Gradient Resistance
The upper most one “Aero-dynamic Resistance” is more or less decided already if the vehicle outer shape is finished. But the other three rolling resistance, acceleration resistance and gradient resistance can be reduced if we give some more interest in it.
To save fuel, we need to reduce vehicle weight (to reduce gradient resistance). Of course we cannot cut our part of vehicle body of functioning part, but we can reduce the unnecessary things in the trunk, for example, golf bag, empty bottles, unnecessary tools, etc. If we can reduce 10% of vehicle weight, we can save 6% of fuel.
To save fuel, we should not drive the vehicle at unnecessary high speed because the acceleration drag is proportional to the square of vehicle speed. If you are driving your car at 80 km/h and for 80 km distance, then it will take one hour to reach. Let’s say your car has consumed five liters of fuel. Now if you increase the speed up to 100 km/h then you can reach the same distance in 48 minutes, but you should consume 60% more fuel to shorten only 12 minutes.
To save the fuel, we should not accelerate and decelerate frequently, rather it is much better to drive at a constant speed. (to reduce acceleration drag.)
Even though a vehicle’s characteristic has been decided during design phase, we can still save a lot of fuel by improving our driving pattern/ behavior.