If you have an automatic car, which is very common nowadays and especially so in the USA, you may be wondering whether or not it is a bad thing to shift gears manually.
Manually shifting your automatic car may be bad under certain circumstances as it can cause extra wear on the car’s internal components, but in other cases it may even be advised, such as when driving on gradients and when turning.
It is key to assess which kinds of transmissions work with specific driving styles. Below, I will discuss the different types of transmissions and how they are affected by the way you use them.
Is It Bad To Shift An Automatic Manually?
It’s not usually bad to shift an automatic manually because most automatics will even have a built-in option for the driver to use the gear selector like a manual stick. This is intended to give the driver a bit more control in adverse conditions, such as on hilly terrain.
However, the transmission is built to be better than the average driver, and the gear changes are designed to occur at the optimum times. So, there really should be no need to shift the gears manually. However, many drivers simply enjoy the feel of changing gears manually and like to be able to do it while driving on hills or around corners for example.
It Can Be A Bad Thing Sometimes
Although not inherently a bad thing, if the driver was to use this as their shifting method all the time, the transmission may be susceptible to some damage. This is simply because it is designed to work as an automatic, and so not using it in this way for extended periods of time could put the transmission under unnecessary stress.
Plus, if the driver is using the transmission manually in a low gear for example, in order to provide engine braking when going down a hill, it is almost guaranteed to cause excess wear to the internals of the car and could damage it. The same thing applies if the driver tries to push the car in low gears, revving the engine beyond its typical range.
This will definitely cause excessive wear on the transmission bands between the internal gears and can therefore result in some very expensive damage. Aggressive shifts at any speed can cause some damage to the transmission, and so it is definitely best to minimize the amount of manual shifting done in an automatic car, even if you think you are perfectly good at shifting.
Essentially, if you shift an automatic car manually in the right way, it's absolutely fine. The only way you'll damage the car is if you are shifting in a way that would damage even a manual car, never mind an automatic.Manual Transmissions Explained
This is the most popular transmission in many parts of the world, while in the USA it is much less common. It is a common transmission used in race cars, due to the amount of control that is offered to the driver. Manuals require a clutch pedal along with an H-pattern shifter to change up and down gears.
A Simple Explanation
When you press the clutch pedal, the clutch disengages from the drive shaft within the car, and then the driver selects which gear they wish to use. Then the clutch pedal is released, and the car is then in a different gear. These three movements are required with every gear change, and they allow the driver to choose when they want to shift up or down.
The clutch is a component that connects the drive shaft to the gears. Pressing the clutch pedal disengages the clutch plate, while releasing the pedal re-engages the clutch plate.The video below goes into great detail about how a manual transmission works. The first 3 minutes or so do a good job of explaining the clutch specifically.
Maximizing A Manual Transmission
Lower gears offer more torque, and therefore more power, but only up to certain speeds. This is why you start in first gear, and then work your way up through the gears to reach higher speeds. In racing situations, a manual transmission allows the driver to time when they want to downshift for maximum speed through corners, and then only upshift when they have gotten maximum power out of each gear.
This does mean that a manual car can be more difficult to learn how to drive properly, and there is more room for error. However, in a racing situation, having that extra level of control can cut a lot of time from each lap. That is only when you use it effectively, and in most racing situations a manual will be beaten in terms of raw speed by an automatic (as the computer is just better at changing gears).
Sequential manual transmissions also exist, and they typically don't need the clutch to shift after you get into first gear. These are common in NASCAR and rally racing.Automatic Transmissions Explained
Automatic transmissions tend to be faster than manuals as they carry out all of the same steps described above on their own. This means there is no input required from the driver, apart from steering, acceleration, and braking of course. The technology in modern automatic transmissions makes the gear changes smoother and faster than any driver (and they win out in terms of consistency too).
Faster & Easier
Automatic cars are much more common in the USA than manuals, and the same tends to apply in motor racing as well. Although manuals are still popular in some series, automatics tend to be easier to use in high speed situations, and although less control is offered to the driver, they are able to put more of their focus on other aspects of driving without having to consciously change gears.
Although automatic transmissions work faster than humans can change a manual transmission, they will tend to be heavier. This is something that needs to be considered depending on the motorsport, and some motorsports like NASCAR and some drag racers use manual transmissions to save weight (although it’s sequential manual in NASCAR).
Paddle/Sequential Shifting Explained
Finally, we get to the best of both worlds for motor racing – the paddle shifter transmission. This is essentially a semi-automatic system, where the driver does not need to operate a clutch (beyond shifting into first gear). They have the ability to go through the gears using a set of paddle shifters, usually located behind the steering wheel, with the left being used to downshift and the right to go up through the gears.
In automatic road cars, these are sometimes there simply to give the driver the option of whether or not to use them, with the car more than capable of shifting completely on its own. However, in most race cars the driver will be required to use the paddle shifters to change gears. This gives them the extra element of control, but without having to worry about pressing and releasing a clutch pedal.
The Ideal Choice
This extra control, paired with the speed of the gear changes, makes paddle shifters a very popular transmission choice in sports like Formula 1. It allows the drivers to make rapid shifts through up to 8 gears, and this is vital at the speeds at which they drive. It balances ease of use with maximum performance, and so it is a very popular transmission in racing.
Key Fact: F1 drivers can shift gears within 50 milliseconds!
As I mentioned earlier, instead of paddles, there may be a sequential shifter, which functions like an H-pattern gear stick, but only allows a gear change up or down a gear, executed by pushing the shifter forwards to downshift or pulling it backwards to upshift.
Final Thoughts
Although potentially useful in adverse conditions, you generally shouldn’t manually shift your automatic transmission, due to the risk of causing expensive damage to the transmission. You shouldn’t really need to do this anyway!