Should I drive in D or D3?
For most trips, keep the transmission in D (Drive). D3 is a limited-gear setting used for engine braking and extra control on steep grades or slippery surfaces, and should be engaged only when those conditions apply.
What D and D3 do in automatic transmissions
In most automatic transmissions, D uses the full range of gears up to the top gear, allowing smooth shifts and better fuel economy at highway speeds. D3 keeps the transmission in the lower gears (typically up to third) to limit engine speed, provide more engine braking, and improve control at low speeds or on steep descents. Not all cars label it the same; some vehicles use 3 or L instead of D3, and some transmissions with many gears may not offer a dedicated D3 setting at all.
Drive (D)
Drive is the normal mode for everyday driving. The transmission shifts automatically through all available gears as needed based on speed, throttle input, and road conditions. It balances fuel economy and performance and is suitable for most roads and weather.
Drive-3 (D3)
D3 restricts the transmission to lower gears (often up to third). This provides stronger engine braking, more consistent torque at low speeds, and reduces the likelihood of upshifting into higher gears on descents or slippery surfaces. Some models label this setting simply as "3" or "L" instead of D3.
When to use D
Use D for normal driving situations where you want smooth shifts, good fuel economy, and predictable acceleration. The following scenarios are typical for D.
- City and highway cruising with regular acceleration and deceleration.
- Moderate hills with typical traffic where you want comfortable, efficient shifts.
- Dry or damp conditions where explicit engine braking is not necessary.
- Long highway trips where you prefer the transmission to select higher gears for efficiency.
In most cases, D provides the best balance between comfort, efficiency, and performance for everyday driving conditions.
When to use D3
Drive-3 is useful when you need more control from the engine, especially on downhills or in slippery conditions, or when towing or starting on steep grades. Consider the scenarios below.
- Steep downhill grades where engine braking helps keep speed in check and reduces brake wear.
- Snow, ice, or loose surfaces where keeping the car in lower gears reduces wheel spin and improves grip.
- Towing or pulling a heavy load where extra torque at lower speeds helps maintain control without over-revving the engine.
- Starting on steep or uneven surfaces where avoiding a rapid shift into higher gears helps prevent stalling.
Always consult your vehicle’s owner manual, as some models use different nomenclature or may not offer a D3 setting at all.
Other considerations and safety tips
Transmission behavior can vary by make and model. In many modern cars with eight or more gears, D3 is still present, but some drivers rely on other features such as hill descent control or low-range modes for similar purposes. If you’re unsure, try the modes on a quiet road and observe how the car responds, or consult the manual.
Summary
For everyday driving, D is usually the best choice. D3 is a specialized setting for engine braking and better control on steep grades, slippery surfaces, or when towing. Use it intentionally and switch back to D when conditions return to normal. Always prioritize safety and consult your owner’s manual for your specific model.
Is it better to drive in D or D3?
Use D. The only time D4 or D3 are needed, is if the transmission is gear hunting on steep inclines, or for engine braking on steep declines. Otherwise, there's no reason not to drive in D.
Is D3 the same as overdrive?
Currently, the D is 'overdrive' in almost all vehicles – the main purpose of which is to save fuel. Driving the car in this gear rather than the lower modes means you can have nearly 15% improved gas mileage.
Is it okay to drive in AWD on the highway?
Yes, you can use all-wheel drive (AWD) on the highway; in fact, that is what it is designed for. AWD systems automatically distribute power to all four wheels to provide better traction and stability on paved roads, especially in wet, icy, or snowy conditions. Unlike four-wheel drive (4WD) systems that are sometimes restricted to low speeds or specific surfaces, most AWD systems are designed to be used at highway speeds and on dry pavement.
How AWD works on the highway
- Automatic operation: Most AWD systems work automatically without any input from the driver.
- Power distribution: The system monitors road conditions and automatically adjusts the power sent to each wheel as needed.
- Highway efficiency: On dry roads, some AWD systems may only send power to the front wheels to improve fuel efficiency.
- Improved stability: During slippery conditions, the system will send power to the wheels that have the most traction, helping to prevent wheel spin and improve stability.
When to use AWD
- Daily driving: AWD provides added security for everyday driving, especially if you live in an area with frequent rain or snow.
- Variable conditions: It's beneficial in situations like driving on wet roads, during winter storms, or on gravel and dirt roads.
When to use 4WD
- Off-roading: 4WD is better suited for off-road driving and extreme conditions that require more torque and control.
- Heavy towing: 4WD systems are designed for heavier loads and more demanding tasks.
- Restricted speeds: Some 4WD systems, especially those with a "4-low" setting, are not meant for high speeds on dry pavement and can cause drivetrain binding or damage if used improperly, notes this YouTube video.
Does using D3 save fuel?
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.
