+2 votes
Recently there is a tremendous growth in case of auto gear shift cars.My question is , is there any drawbacks in cars which are having autogear shift ,like mileage or any other factor ?
asked Jan 16, 2016 in Mechanical by techdoubt
edited Oct 4, 2018 by ppk | 825 views

3 Answers

+3 votes
Selected Ans.

First let us understand what is manual and automatic transmission in cars. 

In manual transmission cars, the speed of car is changed by the person driving the car by changing the gear in which he is driving the car. 

The higher the gear the higher the speed of car. 

In automatic transmission cars, gear changing part which is done by humans is not present, hence, the car gains speed only when you press the acceleration pedal. Here there is no need of changing gears by humans. It happens automatically. 

Some of the advantages of automatic transmission over manual transmission are:

  1. Driver is at ease of driving
  2. Driver has more comfort
  3. Easy to learn driving
  4. Less maintainance

But in manual transmission cars:

1. Driver have better control over the car then in automatic one.

2. In automatic transmission car there is a component called torque convertor which is used to drive the car. But it runs even when car is not in motion and hence burns extra fuel. Since, manual cars do not have such a component in its system hence they burn less fuel then automatic cars and have more mileage.

3. Manual cars are easy to use in traffic roads.

Main disadvantage of manual cars is they are difficult to learn and operating is difficult.

answered Jan 18, 2016 by Faisal Magdum
edited Apr 18, 2016 by slow_learner
+1 vote
Automatic Gear Shift Cars, nowadays are very trending. In Big cities mainly, where there are too much slow moving traffic, the effort in driving is significantly less. No need of pressing the Clutch and changing the gear again and again. Moreover, it is easy to learn driving for the beginners from this and suitable for people who are not perfectly able.

However, there are quite many disadvantages of these Auto-Gear Cars. These cars mainly use Torque Converters for shifting of gears automatically. Talking simply, Torque converter is mainly a box filled with fluid, consisting of Impeller,Turbine and Stator. It uses Engine power to drive the Impeller blades and then the fluid inside the box moves radially due to centrifugal force. This fluid makes the blades of the Turbine to move and transfer the torque to the transmission through Stator.

As Auto-gear shift cars uses fluid for the transfer of torque inside the torque converter, there is a much more power loss in this case as compared to manual one. As a result, there is a significant decrease in the mileage, resulting in more fuel consumption and hence more costly driving. Moreover, these cars are costlier initially too in purchasing cost, and have a higher maintenance cost. Also, Automatic transmission decides the gear changing speeds and changes it automatically, so the driver does not have liberty to choose what gear he wants to drive in. I the car is running on highways, where there is no need of changing gears because of traffic or any other factor, then in that case Auto-gear shift cars are worst as they consume excess fuel and do not even give the sporty feeling to the drivers.
answered Jan 17, 2016 by avashesh11june
reshown Jul 23, 2016 by slow_learner
+1 vote
Cars with manual transmission used to get significantly better mileage as compared with automatic gear cars. A major factor that halted the mileage of cars that use automatic transmissions was the use of a torque convertor that coupled the engine between the mechanical gears. Manual transmissions don’t have this convertor and use a clutch instead. The torque convertor was never 100% effective when the car was in motion, causing cars to lose more power and burn more fuel on the highway than cars with manual transmissions. So manual transmission have better mileage than automatic gear cars.
answered Jan 19, 2016 by shorabh