D3 specifications in automatic car
What does D3 mean in an automatic car?
D3 is a specific mode you can shift into on some automatic transmission vehicles (usually Hondas) that is useful for driving on steep hills, driving in stop-and-go traffic, or driving on slippery roads.
What does D3 mean on a car ?
Selecting D3 with an automatic transmission will restrict the transmission to using only the first three gears. This gives you more control over which gears your car uses, rather than letting the computer choose the gear.
Using D3 can be beneficial under certain driving conditions such as:
1. Selecting D3 uses engine braking for driving on steep hills. This can reduce brake and brake pad wear.
2. Selecting D3 in stop-and-go traffic will prevent the vehicle from shifting into higher gears, resulting in less fuel consumption.
3. D3 is recommended when towing a trailer on mountain roads.
You can check your owner's manual for specific instructions on when to use D3 for your specific model.
Only some models have a D3 selection on the gear lever. Many modern cars rely on the computer to determine the optimum speed.
What is the difference between D3 and D?
When "D" is selected, the vehicle automatically shifts to the optimal gear based on the current speed and acceleration.
In "D" mode, the vehicle may shift into higher gears to warm up the engine faster in cold weather.
When "D3" is selected, the vehicle will automatically shift through the first three gears, but will not shift into a higher gear.
How to switch to D3
Typically, you'll take your foot off the accelerator and move the shift lever to D3. Some cars have a button on the shift lever for D3 (an example of this is the 2009 Ridgeline).
Avoid pressing the accelerator pedal at the same time as shifting, as this may damage the transmission.
When not using D3 while driving
Under normal driving conditions, it is usually better to use the "D" gear selection rather than D3.
The D3 is not ideal for normal highway driving , as the engine will have higher RPMs in lower gears and consume more fuel.
D3 should not be used when towing a trailer under normal road conditions, as it can cause the transmission fluid temperature to increase and cause overheating (source: 2009 Honda Ridgeline Owner's Manual).
How does D3 affect top speed?
The car in D3 mode cannot reach its top speed because it is limited to the first three gears.
For example, the top speed of a Honda Civic EX is 112 when D3 is selected.
How does D3 affect fuel efficiency?
Using D3 can have a negative impact on fuel efficiency as the vehicle will be limited to using the first three gears and will not be able to shift into higher gears at high speeds.
Vehicles with D3 selector
The D3 selector is common on older Honda models. On newer models, the D3 position has been replaced with the letters "S" and "L".
Some examples of cars that have a D3 selector are:
Honda Civic
Honda Ridgeline
Honda CR-V
Honda Pilot