What Happens When You Shift Gears Without Stopping? (Explained For Beginners)

One of the things that drivers are often taught as early as when they are still learning how to drive is to make sure that you stop when you are shifting gears.

This applies to those who are driving automatic transmission cars as you can actually shift gears while driving a manual transmission car.

What happens when you shift gears without stopping? Will that actually blow your engine up or ruin your transmission?

Nothing will happen if you shift the gear without stopping especially if you shifted into reverse while you are moving forward. That’s because you can’t shift your gear into reverse or park when you are moving forward. Meanwhile, shifting into neutral won’t damage your engine in any way.

While there is a truth in relation to the need to come to a full stop before shifting, this only applies to when you are shifting to reverse or park.

However, there is no need to follow that rule when you are shifting to neutral because this will not damage your engine in any way.

But let’s look at this from a more in-depth perspective so that we will learn why or why not you can or cannot shift gears without stopping.

Can you change gears in an automatic car while driving?

Learning how to drive and what you need to do while you are driving can be tedious especially because there are plenty of do’s and don’t’s that you need to keep in mind at the start.

While this should end up as something that’s second nature to someone who has already learned how to properly drive, there are still some things that people tend to overlook even when they have already become seasoned road warriors.

In relation to that, one of the basics that people are taught when they learn how to drive using an automatic transmission car is that they should not change gears while moving.

This isn’t too much of an issue for those driving a manual transmission because you can change gears while your car is moving forward (except when you want to change to reverse) but this is an issue to those who are driving automatic transmissions because of how they are always taught to let the car come to a full stop before changing gears.

As such, can you actually change gears in an automatic car while you are driving or moving forward? Is it even physically possible for you to do so without harming or damaging the engine in any way?

For starters, if we are talking about changing gears from overdrive to the other numbered gears, then you can actually do so because this isn’t technically a gear change but is more of a way for you to tell your transmission to limit itself to certain gears.

As such, you can shift from D to L on your automatic transmission without any problem.

Meanwhile, the major concern that people have is in relation to shifting from D to N (neutral), R (reverse), or P (park) because these are actual gear changes unlike when you are just simply shifting from D to L.

So, can you actually physically shift gears from D to all of the other gears while you are moving?

In relation to neutral, then yes, you can physically shift from D to N. Most people would actually dread to do so but, as far as whether or not you can physically do so, then the answer is yes. However, the same cannot be said when it comes to reverse or park.

So, when it comes to shifting from D or N to reverse or park while your car is moving, then the answer would be that you cannot do so.

And we’re not talking about whether or not you SHOULD do so but we are actually talking about whether or not you CAN physically do so.

According to Popular Mechanics, you cannot physically change gears to R or P while you are moving forward because most shifters come with a physical button that you need to press so that you could actually shift to these gears while you are moving forward. 

And when it comes to gear shifters or transmissions that are electronically controlled, what happens is that the car will actually ignore your request when you try to shift your gear to R or P while you are moving forward, and that’s because the car itself is already electronically programmed to ignore such a request due to how it is inappropriate to do so while you are driving.

As such, when you are moving forward, you can’t physically shift your gear to R or P because of the physical or electronic constraints that are placed on the shifter.

That’s because it is well-understood that there should be no instance where you should be shifting to reverse or park while you are moving forward with your car. In short, as to whether or not you CAN shift your automatic car while driving, the answer is that you CAN’T.

What happens when you shift gears without stopping?

We discussed, there are constraints that will prevent you from shifting your gears to reverse or park while you are driving forward.

This basically means that we are now talking about the other gears which are N, L, or the other numbered D gears on your shifter.

So, what happens when you shift gears without coming to a full stop?

This is something that isn’t a problem for those who are driving stick shifters or manual transmission cars because these cars are built to shift gears while moving.

That’s because you have to shift to higher or lower gears while you are on the go depending on the RPMs that you see on your tachometer.

It would be completely inefficient if you had to come to a full stop just so you could shift to higher or lower gears on a manual transmission.

Meanwhile, for automatic transmission cars, this is quite different because the D or the overdrive gear is already responsible for automatically changing the gears in your transmission.

This means that the other gears on your shifter such as the L or the other numbered D gears are not exactly gear changes but are more like a way for you to specifically tell your car to limit itself to certain gears. 

For example, putting it in L will allow your car to only use the low gear instead of using higher gears, and this becomes useful when you are driving uphill at a slow and steady pace.

As such, it is perfectly alright for you to change gears without stopping if you are changing from D to L or all of the other numbers on the shifter.

However, the grey area here seems to be the neutral gear because that is where some people tend to be a bit more divided in terms of whether or not it is alright for you to shift from overdrive to neutral while you are on the go.

So, is it alright for you to shift to neutral while you are driving?

In relation to that, what you should know is that it’s perfectly alright for you to shift into neutral while you are on the go because that is when then wheels are basically “free moving” in the sense that they won’t be controlled by your acceleration.

The neutral gear essentially disconnects the accelerator from your wheels.

As such, when you are shifting from overdrive to neutral while you are on the go, basically nothing will happen because your car will still continue to move forward as long as it has momentum behind it.

However, stepping on the accelerator will not do anything to it because the neutral gear detaches the wheels from the accelerator so that you won’t even be able to accelerate.

Meanwhile, as to shifting to reverse or park while you are moving, we have already established that there are constraints that will prevent you from doing so.

As such, in theory, it shouldn’t be okay for you to shift to reverse or park while you are moving forward. But you won’t even be able to find out why because you physically can’t shift to those gears while you are driving.

Is it bad for your car to shift gears while driving?

Now that we have established that it is alright for you to shift to L or the other numbers on your shifter while you are moving, does the same hold true when you are shifting from D to N? Will it be bad for you to shift gears to neutral while driving?

Basically, it won’t be bad for you to shift to neutral while you are on the move because nothing will happen especially when you consider that the wheels are now disconnected from the accelerator in this gear.

In fact, it is actually quite useful to shift to neutral when you make the mistake of stepping on the accelerator instead of brake because shifting to neutral will immediately prevent you from accelerating and would thereby prevent an accident on the go.

Now, in relation to shifting to reverse or park while you are driving, then it should be theoretically bad to shift to those gears when you are on the move.

However, because automatic cars are not even built to allow you to shift to neutral or park while you are moving forward, then you wouldn’t even have the opportunity to find out why this can damage your car.

Then again, if you are driving an older automatic transmission that doesn’t come with the feature that will prevent it from shifting to reverse while on the move, what will happen is that the engine will most likely stall.

Sources

Popular Mechanics: If you shift an automatic while driving will you damage your engine?

Motor Biscuit: 5 Things you shouldn’t do in a car with an automatic transmission

Apautoparts.com: Things You Should Never Do With an Automatic Transmission