What Does D3 Mean In a Car? (Explained!)

Sometimes, terminologies concerning cars can be confusing. For instance, if you want to go in-depth into cars, you may have encountered several terms and words that don’t seem to make any sense. For instance, you may have read of the term D3 in an automatic transmission car’s gear stick, and you wondered what it means. So, you may ask:

What does D3 mean in a car? D3 is a term used in automatic transmission drive gear stick, and it’s a gear position similar to D4. It means that you select only the first three gears. Thus, when you shift to D3, your car will automatically shift within the first three gears depending on how your car sees fit.

D3 is a gear position that’s ideal for drivers in a variety of conditions. Thus, if you have no idea what it means, you need to understand when or where you need to shift into this mode or position for a more leisurely drive.

In this article, you’ll see an in-depth take on D3 and some answers to most of the questions you may ask about this matter. After reading, you should get a sense of what D3 means in an automatic transmission car and how you can use it while you’re driving.

Without further ado, let’s get into it!

What Does D3 Mean In a Car

What Does D3 Mean On a Car?

D3 is a term you can find on cars with automatic transmission. You can usually find it as a label along with the modes on a gear stick on an automatic transmission car.

The D3 is a position that’s almost the same as D4. The only difference is the modes of gears you can select in each one.

In general, D3 means a gear position that will make your car choose between the first three gears.

Now, if you’re wondering when you’ll use this gear, you can do so when descending a steep hill. In such a case, the D3 position will help give your proper engine brakes. Further, you can also use D3 when you are in a stop-and-go drive, like driving in traffic.

Lastly, D3 can also prevent the gearbox from cycling between third and fourth speeds. Thus, if you see yourself annoyed when changing the gearbox within the third and fourth speeds, it’s ideal to use D3.

Does D3 Make Your Car Faster?

D3 does not make or help your car to get faster, although it may feel like it does. The reason you sense greater power is because your automobile is in third gear while you’re in D3 at approximately 30-35 mph. As a result, if it were in 4th gear, the RPM would be greater than lower.

In general, you need to remember that D3 is a gear position that allows your engine to choose within the first three gears.

Thus, it can feel a little low in power when in first gear. However, you can feel more power when the gear automatically shifts into the third one. 

In most cases, D3 is ideal when you’re shifting from high speeds to lower ones. For instance, when you need good engine brakes, such as when going down a steep hill or area or when you’re in traffic.

Should I Drive In D or D3?

If you feel confused about whether you would shift to D or D3, you should always consider your driving needs. Thus, it would be best to consider the area where you drive as a factor. 

For instance, D3 is suitable for driving in town or within a city where you can’t speed up like you would on a highway.

In most cases, cities and towns have a speed limit which you can get with third gear. Also, you can experience shortstops from traffic and pedestals. For these kinds of circumstances, you may find D3 an ideal driving gear position.

Locking it up in D3 in and around town is ideal because the D or fourth gear is suited for interstate driving. When driving at a modest speed in third gear, you’ll be able to reach a higher RPM, and the car will respond better.

Also, I mentioned earlier that when descending a steep hill, use D3 to give engine brakes. In stop-and-go driving, D3 can also prevent the gearbox from cycling between third and fourth speeds. 

While ascending high slopes, you’ll have more power, and when descending steep hills, you’ll have more engine braking.

Is It Bad to Drive Your Car in D3?

It’s not wrong to drive your car in D3, but only as long as you do it in the right circumstances. In general, you should only use D3 if you traveled downhill with a load and didn’t want to utilize your brakes as much. 

Because the engine is spinning at a greater rpm, your mileage will suffer. However, D3 would only cause noticeable wear on your transmission if you used it frequently.

D3 position is identical to D4. However, it only selects the first three gears. When descending a steep hill, use D3 to give engine brakes. In stop-and-go driving, D3 can also prevent the gearbox from cycling between third and fourth speeds. If you come to a halt, it does not decelerate to first gear.

Driving in third gear is not advised if the transmission does not have an overdrive capability. Or if the overdrive gear is a gear higher than 4th. 

However, it can happen with slight repercussions such as higher trans temperatures, increased engine wear, etc.

Can You Switch From D to D3 While Driving?

You can switch from D to D3 while driving, but it’s only possible in cars with an overdrive button. With such a feature, you can press the button while driving in D (which is driving above third gear), and it will shift to third gear or D3. 

If you are on D and you are going down a steep road, it’s ideal to shift down to D3. Moreover, if you’re cruising through a town or city, you may shift to D3 all the way. 

This gear position will give you and your car better driving. Since D or fourth gear is designed for interstate driving, shifting in D3 in and around town is perfect. 

When driving in third gear at a low pace, you’ll be able to attain greater RPMs, and the automobile will respond more quickly.


In a nutshell, D3 is a gear position you can find in an automatic transmission car. It is a gear position similar to D4 that is used in automatic transmission drive gear sticks. The only difference is that you choose the first three gears in this position. As a result, when you shift to D3, your automobile will automatically change between the first three speeds as needed.

D3 is an appropriate gear level for drivers in several situations. Now, you can take it as a rule of thumb to use this gear whenever you’re driving within a city or town or when you’re driving down a steep hill. 

The gear implies a good engine brake, so you can slow down and go to a complete stop without using much of your brake.

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Image credits – Canva

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My name is Hank, and I've been in the automotive industry for 27 years. I've been working in my own auto repair shop for the last 13 years, and now I want to help you here, on my blog. Let me know if you have any questions. Read more