O/D Off Meaning: How to Use O/D Off Effectively

OverDrive is a feature that all cars today have and helps you save more fuel. It also provides better performance and reduces engine breakdown.

Overdrive has a gear design and operates on electric power, which is permanently attached to your vehicle's powertrain. However, not everyone understands the concept, knows how to use Overdrive effectively.

This article will help you better understand the details and notes when using it for your car. Let's get right into the details!

Introduction to Overdrive


O/D Meaning

OD stands for Overdrive, responsible for displaying the vehicle's performance at a sustained speed with low RPM. ‘Revolutions Per Minute’ is in revolutions per minute. It will help you save more fuel, limit engine noise and wear on the car's suspension.

However, 'overdrive' has several other meanings that act as a single product on the vehicle, helping to reduce strain on the engine because of this feature.

The machine will operate more efficiently and optimally. Regarding gear ratios, it also produces a lot of power, even if you use the car in low gear.

For example, if the car's gear ratio is about 0.7 to 0.85, your vehicle can travel at high speed with low RPM. At the same time, the overdrive gear operates efficiently with a quick one revolution time. Thus, when driving on the highway, your car does not need to accelerate continuously.

What does O/D Off mean?

O/D off is the off state of the overdrive, the overdrive gear is inactive, and the torque is not locked. At the same time, you can directly press the button on the gear lever with the symbol OD.

O/D stands for OverDrive. Here the limit is the gear ratio, at 1.00:1. O/D On ie allows the car to run in gearbox mode with a gear ratio exceeding the limit of 1.00:1, O/D Off is limited to 1.00:1.

For example, a 6-speed automatic transmission has the following gear ratio structure:

  • Number 1: 2.97:1
  • Number 2: 2.07:1
  • Number 3: 1.43:1
  • Number 4: 1.00:1
  • Number 5: 0.84:1
  • Number 6: 0.56 :1

So in this case, O/D On allows the car to run up to 5th and 6th gear, with a gear ratio exceeding the limit of 1.00:1.

When O/D Off, you can only use numbers from 1 to 4 but cannot use numbers 5, 6 for your car.

When O/D is off, you can only use a maximum gear ratio of 1:1 to bring the vehicle to a stop, and the transmission will not go to the ultimate gear it has.

At this time, the engine RPM is higher, the car is stronger. Therefore, if moving normally, the O/D is always On. The driver actively turns off the O/D (to Off) often in situations such as: slowing down in traffic jams, accelerating quickly to overtake, climbing not very high slopes, going downhill... to take advantage of the traction of number 4.

All cars today use automatic transmissions with OD function. When OD is off, you are locked and do not use this function.

The task of the off-state is to help you move better when going uphill when you need to put a low gear to pass another vehicle when climbing a high slope.

How to use O/D Off effectively

First, you need to define the circumstances under which you can use the device, either On or Off. O/D Off will help your car have a reasonable speed when moving in many types of terrain.

You are not using the O/D button when turning the O/D switch off.

At the same time, when you push the button and the starting system helps transfer force to the gears, limiting their operation.

The manufacturer recommends using this driving mode every day because it is beneficial for engine life and less stress on the system.

1. Used O/D when speeding up


Used O/D when speeding up

It would help if you used OD when traveling at speeds higher than 50 mph. When you go over 60 mph on newer cars and 50 mph on older cars, the RPM increases and the engine starts to use more traction. If you turn on the OD Off feature will reduce RPM and limit pressure on the engine.

However, you won't need to use the overdrive when driving in a speed-restricted environment, specifically below 50 mph, because the speed tends to be uneven there. If you use this function properly, and effectively, then the life of the car engine will be greatly increased.

2. Use O/D when going downhill


O/D button on a new car model

When you are going downhill, you need to apply the brake continuously. The brake system needs to work a lot and requires high efficiency. Not only that, even when moving in a residential area, you also put pressure on the brake system, and in those situations will keep the RPM above idle without strain the brakes and the engine if you use the O/D in time.

3. When not to use O/D in a car?

It would help if you did not use O/D when driving below 50 mph, uphill, or towing a trailer. This activity will affect your device and movement, reducing transmission efficiency. In some bad cases, it can cost you a lot to repair and replace the device.

On the contrary, using O/D correctly will help save fuel and increase the life of the device. This video is for detailed guides:

Video created by Ben Lau

Frequently Asked Questions

1. Is it safe when driving with O/D Off?

When your car uses Overdrive Off, you and the vehicle are safe. The overdrive feature makes it easier to navigate through rugged mountainous terrain. You need to move slowly and use traction to ensure the safety of yourself and others.

However, Overdrive Off will not be suitable for driving on the highway. You need a high speed, so O/D should be turned on to help you limit unnecessary fuel consumption.

When Overdrive is on, the noise from the engine reduces, the driving speed is faster and smoother. In contrast, Overdrive in Off mode speed will be average, consuming more fuel.

2. What happens if O/D is Off?

Overdrive has a gear design that helps the car engine limit pressure. The machine will work well, stably, with the optimal level that the car can meet.

The low gears cause the engine to generate more power, and the transmission ratio must also increase. Turning overdrive on or off depends on the type of road and terrain you're traveling on for the best driving experience.

3. When do you know if Overdrive is On or Off?

You can thoroughly check the status of the overdrive quickly. You need to change from the state of the product moving on the highway. When speed increases, Overdrive turns off, vice versa if speed decreases, Overdrive is on.

Initially, when not starting, your transmission will be in low gear. Then, if you want to move on the road, use the accelerator and brake the engine. At the same time, depending on the terrain, you can turn OD on or off if you want.

If the OD light does not turn off, you can take your car to a repair shop that will have a technician check it out for you.

4. Can Overdrive mess up transmission?

Overdrive has a high ability to limit engine wear and save more fuel when used.

However, it does not happen in most cases, and this possibility only occurs when using light torque. Using torque in overdrive causes the car's engine to wear out.

Then the gearbox and clutch were damaged when using a lot of torque during the vehicle's deceleration.

5. Does Overdrive Off make the car faster?

The answer is no. Overdrive Off does not make your car go faster than average. The effect of the product is to change the vehicle frequency to high, helping to manage fuel well and save more fuel.

O/D off will help you use the vehicle as a tow truck and drive up or downhill. In addition, when you turn off the engine, the transmission ratio will be too low.

6. What damage does using the incorrect O/D cause?

When the O/D mode is active it will allow you to use the entire transmission system. Furthermore, O/D also helps to optimize transmission life and increase fuel efficiency.

However, if you use it incorrectly, such as while towing a trailer, driving uphill, or accelerating below 50 mph, this will cause damage that is hard to repair.


This article has provided about O/D Off meaning and its usage. The concept of O/D is relatively simple and easy to understand. We hope you can effectively apply the above information.

At the same time, using O/D is an effective method to help you save more fuel and costs. Use case you can rely on moving terrain; O/D will be a good choice if the terrain is flat. On the contrary, you should switch to O/D off mode to make it easier to control when driving on steep and rugged terrain.

Knowing how to use the car's mode most optimally will bring you the most comfortable and enjoyable experience.

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