Modern-day vehicles are equipped with state-of-the-art technology to make driving safer and easier. Unfortunately, these functions are often overlooked and underutilized.
A feature that’s seldom talked about in automatic transmission vehicles is the different gears. It’s understandable as to why because cruising on a highway in D (drive) mode is often enough to get by. However, the D1, D2, and D3 gears all have their purpose and use that drivers aren’t aware of. Let’s explore the D3 gear.
What Does D3 Mean in a Car?
The D3 you see on the gear stick on an automatic transmission car stands for Drive 3. Using the first three gears (gears one to three), it sets the gearbox with the third gear as its highest setting.
You’ll also get better power and a wider rotation per minute (RPM) range with D3. RPM measures how fast the vehicle operates at a given time, meaning your vehicle uses more power in D3 mode compared to other gears.
What Is the Difference Between D3 and D?
D3 prevents shifting to higher gears, while D occasionally shifts to a higher gear to warm up the engine in cold weather or when the car computer deems it necessary.
How to Use D3
To take advantage of D3 mode and its benefits, follow the steps below:
- Step 1: Start your car and use the D (drive) mode first. The vehicle will use the lowest gear possible first to provide the ideal torque for moving slowly.
- Step 2: Accelerate to 20 to 25 miles per hour before shifting to D3.
- Step 3: Slightly let off the accelerator pedal to avoid damaging the transmission. Then, press the D3 button on your gear stick to shift.
- Step 4: If you’re about to slow down or come to a stop, shift back to drive mode.
Advantages of Using D3
Like other gears, D3 was designed with certain advantages in mind:
Engine Braking
The D3 gear helps activate engine braking when traversing downhills, easing the strain on regular brakes and brake pads.
Reduced Maintenance Cost
The reduced stress on your brake system and brake pads prolongs their lifespan, which means you won’t have to spend as much time or money on maintenance.
Better Power
D3 delivers more power, as it increases your vehicle’s RPM. It’s ideal when going uphill where speed isn’t as big of a factor in driving.
Safer Drive
D3 gives you better control of your vehicle with its automatic engine brakes. It also lowers the risk of slipping because of the low speed and higher RPM.
When Should You Use D3?
Driving in D3 mode is useful when you’re driving uphill, downhill, in stop-and-go traffic, and on slippery roads.
Downhills
D3 enables engine braking, preventing your vehicle from running at high speeds. The mode restricts the airflow, which causes a high manifold vacuum that leads to your car decelerating.
This is important, especially for newer drivers, because driving at high speeds on a descent could be dangerous.
Uphills
Similar to driving downhills, it’s better to traverse uphills slowly. D3 mode helps you achieve the optimal speed to climb steep roads. Additionally, the low gear provides your car with more power to climb.
D3 also prevents slipping because it keeps the transmission in the same gear. Automatically changing gears could lead to a loss in traction, so it’s ideal to stay consistent with your transmission.
Stop-and-Go Traffic
Using D3 consumes less fuel since it prevents the car from shifting into higher gears. This is ideal for crowded cities and stop-and-go traffic for better fuel economy.
Slippery Road
D3 limits the transmission to the first three gears, which restricts wheel slippage and maintains a steady pace. It can help you traverse slippery roads where you could lose traction.
When Should You Not Use D3?
Of course, there are also circumstances where it’s better to use other gears instead of D3, specifically when driving on the highway and towing a trailer.
Highway Driving
Avoid using D3 when you’re driving on the highway where driving at high speeds is expected. In this gear, you’re using more power and less speed, making your vehicle consume more fuel relative to your speed.
Towing
When you’re towing a trailer in normal road conditions, don’t use the D3 mode, as it could increase the temperature of the transmission fluid. This could lead to overheating, which causes transmission damage.
While transmission damage on automatic transmission vehicles isn’t as severe compared to manual transmission cars, it will still make for difficulties in driving. You’ll have a hard time shifting gears, making for dangerous driving conditions.
Do All Automatic Transmission Vehicles Have D3?
Not all automatic transmission cars have D3 because most modern cars have computers that determine the optimal gear depending on the situation. Some examples of models that have D3 are as follows:
How Fast Should I Drive in D3?
You should avoid driving faster than 30 mph when using D3. Anything above that will affect your fuel consumption, as your vehicle’s using more power and less speed.
Can I Switch From D to D3 While Driving?
You can switch from D to D3 while driving as long as you maintain the optimal driving speed of 20 to 25 mph. However, it’s best to let off the accelerator pedal first for smooth shifting. Some cars also have a button that automatically switches to D3.
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Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.
