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Which 2021 half-ton trucks have 4WD Auto, what it is and when to use it

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One of the more significant, and often overlooked, improvements for 4WD trucks has been the introduction of a 4WD Auto setting. This feature has quickly become a fan favorite, yet not every full-size truck has it. And, frankly, not everyone understands how to use it.

So, before we get to a list of trucks that have it and how they work, let’s first discuss what 4WD Auto actually is.

What is 4WD Auto?

For years, 4WD trucks had a simple operation to engage the front axles when needed through a transfer case. This transfer case, linking the rear driveshaft with a front driveshaft, offered three settings — 2Hi, 4Hi and 4Lo. 

Most of the time, truck owners drove in 2Hi and would only occasionally use 4Hi when they needed it in muddy or slick situations. The last setting, 4Lo, is for serious off-road use and is often viewed as only needed in emergencies. 

In the past decade, the new 4WD Auto setting has made its way into half-ton trucks. This setting is similar to the thinking behind all-wheel drive (AWD) you find in SUVs. The idea is the computer senses slippage and then engages the front wheels automatically when needed.

The best part of this operation is it is seamless and gives the driver more confidence in all conditions. Plus, the systems don’t bind or have “wheel hop” like a traditional 4WD system since they continuously vary the clutch engagement to give you a smoother ride. If you have ever experienced this binding, which feels like the truck is fighting itself to make a turn since both front wheels are trying to turn at the same rate rather than the outside wheel traveling more to help you make the turn, you know it isn’t a smooth experience. 

Most truck owners, whether they admit it or not, have all faced driving situations where they should have been in 4Hi but forgot about turning it on. This would have made those slippery experiences less nerve racking — and that’s part of the reason for the existence of 4WD Auto.

Trucks with 4WD Auto

If you like what you are reading and are curious about trucks with 4WD Auto, the list is pretty short: Ford, GM and Ram trucks all have it. Nissan and Toyota, surprisingly with its new 2022 Tundra, both don’t have this feature.

Specifically, you’ll find the 4WD Auto setting on all Ford F-150, Chevy Silverado 1500, GMC Sierra 1500 and Ram 1500 trucks. It is often found in the grouping for 4WD settings as either a button or a turn dial to select it.

How it actually works 

The Ford, GM and Ram systems all generally work the same. 

Each system uses a clutch to engage the front wheels for better traction, and this is decided through the computer’s software system using a complex series of algorithms. When slippage occurs or the system thinks you need more torque on the front wheels, the system engages the clutch, which then sends power to the front wheels. After the truck is back under control, the clutch is disengaged putting the truck back into 2Hi — sending all the power back to the rear wheels. 

The software is designed to be forward-thinking and works to prevent slippage at all. Also, the power sent to the front wheels can be varied from 0 to 100%, depending on the truck’s needs.

Finally, like we mentioned above, the clutch is continuously varied, meaning no binding up and no wheel hop. This is due to the system letting the outside wheel travel more freely — unlike when you are in 4Hi and have the front wheels engaged 100%, limiting the turn radius.

When should you use it?

Another big question about 4WD Auto is when you should use it. The answer varies.

For example, GMC says in the Sierra’s owner’s manual to “use when road surface conditions are variable. When driving in AUTO, the front axle is engaged, and the vehicle’s power is sent to the front and rear wheels automatically based on driving conditions. This setting provides slightly lower fuel economy than 2Hi.”

Ford doesn’t specify when to use it or not. Rather the F-150 manual says it is for “increased traction in varying on-road conditions.” Also, certain drive modes automatically shift the truck into 4WD Auto.

Ram echoes Ford in its 1500 manual, saying you can use 4WD Auto in a variety of on-road conditions for better traction.

The bottom line on 4WD Auto

While every truck maker acknowledges using 2Hi is the best setting for fuel economy, the peace of mind of having the truck always in 4WD Auto is a big win for a lot of truck owners. In fact, quite often, owners tell us they always drive around with 4WD Auto since you never know when you might need the extra traction.

We think that’s probably a good idea for many drivers.

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Tim Esterdahl

Automotive Journalist Tim Esterdahl has been a lover of trucks and SUVs for years. He has covered the industry since 2011 and has pieces in many national magazines and newspapers. In his spare time, he is often found tinkering on his '62 C10 pickup, playing golf, going hunting and hanging out with his wife and kids in Nebraska.

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