When should you shift gears in an automatic

Many of us grew up learning how to drive stick-shift cars. We got used to smoothly changing gears up and down as necessary while we were driving. The question is, with manual transmissions becoming basically extinct, can you change gears while driving in an automatic car? We have searched for the answer to this question so that you don't have to!

You can manually change to some gears while driving an automatic car. Other gears you should never switch to unless you are completely stopped as it can severely damage your engine. Most modern cars thankfully won't let you switch to some gears while driving to stop any mechanical disasters. For the most part, automatic cars up and downshift for you so you don't have to worry about it. 

Automatic cars all have varying shifters and gears that you can use. There is a wide variety of different "modes" that come with automatic cars that have different uses. It is very important to know the limitations of shifting with your specific car. If you do it wrong, it can cost you a lot of money and even more stress later on. Keep reading down below so you can know the complete capabilities of your automatic car's transmission!

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Shifting Your Automatic Car While Driving

Depending on what gear you're trying to get to, you're even encouraged to shift your car while driving. You just have to know when those situations are. The transmission is no different than any other part of your car. You want to use it properly, and not wear it out any faster than you have to.

How Do You Manually Shift An Automatic Transmission?

Before talking about the ins and outs of shifting while driving an automatic car, it's important to know how to. Depending on your car, the shifter may have a button of some sort on it that you need to press to move the shifter. If this is true for your car, then press the button before shifting. Then you simply have to move the shifter to the desired gear. You may want to let off the gas while doing this. Your car should also, thankfully, restrict which gears you can do this with while driving. 

What Gears Can You Shift To While Driving An Automatic?

This can differ depending on the gear modes that are available in your car. Usually, cars will have a sport mode or economy mode, or some variations of those. You can and should shift to those while driving but only during the appropriate times. They are meant to optimize your car's performance.

However, if you don't use them at the appropriate times, shifting them can hurt your car. You should also be able to shift to neutral when needed, like if your car dies on the road while driving. 

What Gears Shouldn't You Shift To While Driving?

This might seem like common sense, but for the well-being of your car, it's important to point out. You should never try to shift into park or reverse while driving. As mentioned above, the majority of automatic cars on the road today won't let you do this anyway. Which is good because it could severely damage your transmission.

You shouldn't even switch in and out of these two gears when moving at all. Chances are your car will let you switch from reverse to drive while moving slowly. Even shifting between these gears at a low speed will wear down your transmission faster. 

Do You Ever Need To Shift While Driving An Automatic?

For the most part, not really. Automatic transmissions are designed to do their job more efficiently on their own than with us helping. That's why manual transmissions aren't really around anymore. Automatic ones do a better job at shifting than any human can.

You can use the driving modes mentioned above when it is appropriate to do so. Even with those, you should exercise caution so that your transmission doesn't see any unnecessary wear from it. 

More Automatic Transmission Questions

Learning if you can shift your automatic car while driving is just one piece of the puzzle. It's important to know in detail when and how it's appropriate to use that shifter while driving. Especially since many individuals aren't even sure what those extra letters next to the shifter even stand for. 

What Is S Mode In An Automatic Car?

S mode stands for "sport" mode. Even if you don't have a fancy sports car it may still be handy to you. Sport mode does a few different things that change your driving experience. The first thing it does is change when your automatic transmission decides to shift. Usually, automatic transmissions shift at fairly low RPMs. Sport mode makes it shift at a higher RPM. This changes the performance level of the car and gives many a smoother driving experience.

It also affects the suspension and handling capabilities. This is why it can be useful for navigating winding or twisting roads. Like when you're driving through mountains for example. It makes handling your car and normal speeds a bit more comfortable in these areas. 

Can You Shift From D To S While Driving?

Yes, you can shift from drive to sport mode while driving. This should only be done in situations like the ones explained above. You also want to avoid making this transition while completely pressing down on the gas pedal. This might be damaging for the transmission. Your car's computer should stop anything damaging from happening in this instance but better safe than sorry. 

How Do Automatic Cars Know When To Change Gears?

A lot goes into making an automatic transmission work the way that it does. Basically, when the RPM of your car gets to a certain accelerating speed it knows when your upshift. Also, when the RPM gets low enough, your transmission knows when to downshift. The transmission has sensors in it that tell it when these points have been hit so it knows when to shift. 

Why Does My Car Jerk When Shifting Gears With An Automatic Transmission?

Unfortunately, this is a fairly common problem with automatic vehicles. This can mean that there is already a problem with your transmission, or if you don't fix it soon there will be. One of the leading causes of this is that your car is low on transmission fluid. Either that or the fluid is very old and dirty and needs to be changed. There may also be a part inside of the transmission that is going bad. If it's not the fluid then it will save you a huge problem and bill later on if you take it into the shop now. 

Is There Anything You Can Do If You Really Want To Manually Shift?

Aside from getting a specially made or older manual transmission car, there is another option. Many newer automatic cars come with the option to manually shift them while driving! If the car has this, it will show a spot next to your shifter with a plus and minus sign. Sometimes there will also be an "m" next to them. Putting your automatic transmission into this mode will allow you to upshift and downshift on your own! 

Finishing Up

You can change gears while driving your automatic vehicle. Your car thankfully shouldn't let you shift to the most damaging gears like reverse and park. When shifting to the other options, it's important to know when it's the appropriate time to do so. Not shifting in the correct situations can easily start to damage your automatic transmission. Now that you know how to use your automatic transmission as effectively as possible, all that's left is to take a road trip!

For more transmission information make sure to click on the links below:

When Should You Check Transmission Fluid?

What Pickup Trucks Come In Manual Transmission?

Does Toyota RAV4 Have CVT Transmission? [Various Models Reviewed]

The first truly automatic transmissions appeared in 1948 Oldsmobiles. According to Edmunds, a leading American online automotive resource information company, in 2019 more than 98 percent of all cars sold in the U.S. came with automatic transmissions.

Modern automatic transmissions are quieter, shift faster, feature more gears (up to 10) for quicker acceleration, help reduce tailpipe emissions and get better fuel mileage than manual transmissions.

Manual vs. Automatic Transmission: What’s the Difference?

Although manual and automatic transmissions do the same thing — mesh and release interlocking gearsets that ultimately turn the drive wheels — they do so in different ways.

Shifting gears on a manual transmission requires the driver to depress the clutch pedal, disengaging the engine from the transmission. The driver then uses the gear shifter to physically move gearsets inside the transmission.

With automatic transmissions, once you place the transmission into drive, gear movement and shifting become, well, automatic. Driving an automatic transmission allows drivers to keep both hands on the steering wheel, making driving safer, simpler and more pleasurable.

How Does an Automatic Transmission Work?

(Note: What follows is extremely technical. If you’re not interested in the whys and hows, scroll down to the next section.)

Automatic transmissions shift gears using pressurized automatic transmission fluid (ATF). A valve body routs the fluid through a sophisticated network of channels and passageways to various internal friction bands, pistons and multiple disc clutch packs that lock and unlock ingenious compound-planetary gearsets.

Transmission gear, and gear ratios, are determined by which parts of the gearsets are free-wheeling or held stationary by the bands and/or clutch packs. Automatic transmission shifts, up and down, are controlled by engine load, throttle position and other driving factors.

Pre-computer-controlled vehicles used mechanical vacuum modulators, governors and cables to control shift points. Today’s vehicles use numerous input sensors that send data to a computer (ECM).

The ECM manages shift points by turning shift solenoids inside the transmission on and off. Solenoids direct ATF through the valve body. The valve body then routes the ATF to the correct passageways, where it applies or releases the bands and or clutch packs.

Manually downshifting an automatic transmission into a lower gear slows the vehicle. Lower gear ratios reduce the output speed of the transmission but increases torque, giving you better control of your vehicle under certain driving conditions.

Shifting into “L” or first gear “1” keeps the transmission from upshifting automatically. Automatic downshifting, also known as engine braking, takes place when you remove your foot from the accelerator.

Engine braking happens when a slower rotating engine engages a faster spinning transmission — basically, reverse acceleration. Removing your foot from the accelerator closes the throttle, restricting engine air flow, which builds up a strong vacuum in the intake manifold.

Pistons working against high vacuum lose power, lowering engine RPMs, slowing your vehicle without the driver stepping on the brake pedal. Because you’re not pushing down as often on the brake pedal, slowing the vehicle via engine braking may extend the life of your brake pads and rotors.

On the other hand, automatic overdrive transmissions, or automatics with a locking torque converter clutch, have gear ratios greater than high gear or direct drive (1:1, one transmission rotation for every engine rotation). This reduces engine RPMs at highway speed to increase fuel economy, and lets the transmission automatically downshift when accelerating at highway speeds.

You should downshift an automatic transmission in low traction situations, especially when your transmission shifts through all gears, spinning the wheels though your vehicle isn’t moving. Racing the engine and spinning your wheels will overheat transmission fluid, quickly damaging the transmission, ruining tires and cause premature engine and differential gear wear.

Manually downshifting an automatic transmission locks gearsets and clutch packs into a lower gear range that produces more torque and better maneuverability when:

More recently, Grade Assist is becoming standard on cars and light trucks. Originally found on construction equipment, Grade Assist uses sensors and other electronics to automatically control transmission shifting and braking. This helps drivers maintain a safe speed when driving down long, steep inclines.

Automatic Transmission Shifter Numbers and Letters

Virtually all automatic transmission shifters have P, R, N, D. Depending on your vehicle, shifters may have D, 3, 2, 1, while most modern vehicles only have an L after the D.

So what do these letters and numbers mean? P, R, N, D, L = Park, Reverse, Neutral, Drive, Low, or as automotive engineers affectionately call it “prindel.” Numbers usually indicate the highest gear a transmission will automatically shift into.

Using the D, 1, 2, 3 example, starting out in “1” means the transmission will not shift out of low gear, “2” means it would shift from low to second gear. In the D, 1, 2, 3 example, driving in “3” will get you into the highest gear, but won’t engage the overdrive unit or locking torque converter until you shift into “D.”

The Final Word

Today’s sporty cars with continuously variable speed automatic transmissions (CVT) can have steering wheel-mounted paddle shifters that electronically shift an automatic transmission.

Originally developed for race cars, paddle shifters give drivers a sense of control and the ability to shift gears without pushing on a clutch pedal. ECMs on vehicles with paddle shifters are programmed to keep drivers from aggressive shifting that can damage their transmission.

Originally Published: November 11, 2021