When to Use 4wd Auto Ram 1500 – 4A Guidelines

Gone are the days when 4-wheel drives consisted of a basic 4wd system comprising 2H, 4H, and 4Lo. With modern 4WDs becoming more sophisticated, it is as if we need to relearn the rules of driving our 4WDs. With the addition of 4WD-Auto being thrown into the equation, it’s becoming increasingly tricky to know when to use which setting for optimal performance. It has evolved to be more simple yet more complicated.

Ram 1500 4WD Auto should be used when traction consists of a mixture between acceptable grip and low traction areas.

What does the manual say? The manual clearly states that 4WD Auto can safely be used for regular driving, but that it may negatively affect your fuel economy. With fuel prices at an all-time high, that’s a hard pass for me, thanks. With gas prices constantly on the increase, we want to make sure our trucks are running as efficiently as possible. Also, as much as possible, we want to extend the longevity of our 4WD drivetrain to avoid unnecessary warranty claims.

When is it applicable to use 4WD Auto?

Let’s look at a few scenarios where 4WD auto would be best suited.

When to Use 4wd Auto Ram 1500


For regular driving on a high traction surface, I would recommend leaving the vehicle in 2H. This setting will offer the best fuel economy. Even on rainy days, driving on the highways, 2H with Ram’s anti-slip technology should make light work of it. Instead, adjust your speed and extend your following distance. 

Inclement Weather

When driving in inclement wet weather conditions, 4WD auto would be the ideal choice, since road surfaces could possibly consist of a mixture of traction levels. 4WD Auto will negate the need for the driver to constantly read road surface traction since the 4WD Auto will take care of that and engage at a movement notice when necessary. Again, adjust your driving style and speed accordingly, and increase your following distance.

Snow and Ice

The same applies when it’s snowing, 4WD Auto would be the best option. Most Ram owners leave their trucks in 4WD Auto during the winter months when there is constant snow and ice on the roads. The 4WD Auto function will calculate when traction is low and send power to the inside wheels when cornering, thus offering greater stability. Yes, there will be a slight increase in fuel consumption as a trade-off for your safety.


The other scenario that warrants 4WD Auto with your Ram 1500 is when you are towing. 4WD Auto will offer the optimal mix between traction, stability, and efficiency.

What Is 4wd Auto Ram 1500?

When in 4WD Auto, the transfer case is ready to engage the front wheels in the event the vehicle senses the rear wheels have lost traction. 4-Wheel Drive Auto engages 4-Wheel Drive automatically anytime the vehicle loses traction, for extra traction in varying road conditions.

What Is the Difference between 4wd Auto and 4wd High?

4H is when the center diff is locked and the engine power is split between the front and rear axles. In 4H the front wheels will pull the vehicle forward while the rear wheels propel the vehicle simultaneously. 4H is only meant to be used on slippery low traction surfaces such as sand, dirt roads, mud, and snow. Driving in 4H on a high-traction dry surface for extended periods will result in drivetrain binding.

4WD Auto on the other hand only engages the rear wheels, similar to when driving in 2H, until traction is lost. 100% of the power is sent to the rear axle. However, when traction is lost on the rear wheels, the front axle is immediately engaged for improved traction and stability and the drivetrain automatically engages 4H.  Once the vehicle senses traction has been regained in the rear wheels, it disengages the front and the truck reverts back to 2H mode. This is all accomplished within split seconds without any additional input required by the driver.

4wd Auto Vs 2wd – What Do the Owners Say?

Let’s see what the owners have to say when they engage 2H and when they use 4WD Auto.

I use 2wd for normal driving. If their is snow or ice on the roads I will put it in 4 auto and if it gets bad I will use 4 lock. When I had my good years. I would use it in the rain more but I don’t see a need my Michelin’s.


User Feedback/Experience #2

I use Auto most of the time during winter months when there is snow/ice on the roads. 2 hi all other seasons. MPG does drop when in Auto. Roughly 20%.


User Experience #3

For my daily commute, I keep it in 2WD. The only time I will use 4WD auto is if it is raining or snowing or if I am towing something.


User Experience #4

I see no reason to use 4 auto unless it is snowing out… I know when I will or will not need 4×4. If I were to let my wife drive the truck the 4 auto would be nice, since she knows nothing about when/when not to use 4×4. It is a nice feature, but one that I won’t use very often


User Experience #5

I use 2WD almost all the time. I use 4WD Auto if it’s snowing and sticking and traction can be spotty. I use 4Hi if the roads are slick everywhere, but not at highway speeds (if you can go that fast, 2WD is back on). I’ll often go back to 4WD Auto when making tight maneuvers, like parking lots. If I were the off-road type, I might go to 4Lo if I were rock crawling.


How Fast Can You Drive In 4wd Auto

I would recommend as fast as necessary and as slow as possible since the driving surface traction could vary which could upset the driving dynamic of the vehicle if you’re going too fast. Always Ur on the side of caution and don’t become overconfident. 4WD trucks have a tendency to make us feel invincible. Remember the laws of physics still apply and adjusting your driving speed according to the road surface and traction levels is always your best option. A general rule of thumb is, no faster than 60mph when in 4H.

Does Auto 4wd use more gas?

Simply put, yes it does. More drivetrain components rotate when 4WD is engaged. When 4WD Auto is engaged the transfer case keeps the front wheels ready to be activated at a moment’s notice.  For optimal performance and best fuel economy use 2H on dry high traction surfaces. 2H causes less wear and tear on drivetrain components.  4WD vehicles have to send power to each of the vehicle’s wheels, which requires extra energy. 4WD trucks return lower gas mileage than 2WD rivals due to additional drivetrain components making them heavier.




At the end of the day, if you are not sure if the driving scenario requires 4H and when it’s safe enough for 2H, simply leave it in 4 A (auto) mode to be safe and let the TC system take care of matters for you, albeit at a slightly higher consumption rate. If the driving surface is a combination of high and low traction 4A would be the ideal choice.

Jade C.

4-Wheel drives and off-road driving techniques has been my passion for over 20 years. Here we strive to provide the most accurate, up-to-date, information about the functionality, common faults and latest technology built into most 4 Wheel Drives.

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