A short guide on the basics of 4WD and AWD for photographers.

It may surprise some, but I am a huge automotive enthusiast that works auto shows. The idea for an article about four-wheel drive systems arose from my daily interactions at work. Confusion over the smorgasbord of marketing terms describing four-wheel drive (4WD) tops the list of questions. It’s followed closely by understanding the actual need for such a vehicle.


Even the old school AWD systems allow for extra traction – and fun! Shown is a 1995 Eagle Talon.

I am considering trading my beloved front-wheel-drive workhorse for one with extra drive wheels since shifting into landscape photography. After all, who doesn’t like traveling off the beaten path? But is a 4WD like a Jeep Wrangler necessary? Or can the average AWD car fit the bill? Let’s explore our options!

Four-Wheel Drive, All-Wheel-Drive, Oh My!

What is the difference between Four-Wheel Drive (4X4) and All-Wheel-Drive (AWD)? Are they the same? Don’t they use the same parts? The answer is – yeah, well, kind of, not really.

The Jeep Wrangler – considered by many the king of the four-wheel drive and off-road world.

Let’s start with the traditional four-wheel drive, also known as 4X4. This is the term used regarding trucks and traditional SUV’s. All four wheels receive equal power. Great for navigating rough and uneven terrain, but not great on-pavement. When making a turn, the inside wheels turn slower than the outside ones. If power delivery cannot adjust, a wheel hop or chattering occurs. Also, damage to components can occur at higher speeds.

Enter the two-speed transfer case! The “high” setting compensates for the rotational differences. This makes the system ideal for on-road conditions, higher speeds, and inclement weather. Meanwhile, the “low” setting lets you navigate those tougher trails. The addition of center differentials and limited slip differentials mitigate the awkward wheel hop issue further. More on that topic later!

The underside of a Jeep Wrangler shows the basic layout of a typical 4WD SUV.
From left to right: front axle, front driveshaft, connecting to the transfer case (under the black skid plate), transmission, rear driveshaft, and the rear axle. Photo courtesy of Jeep.

AWD-I, S-AWC, Intelligent AWD, 4Matic, 4Motion, Quattro, x-Drive – Yikes!!

Forget all these marketing terms, as they mean the same thing. All-wheel-drive (AWD) is an evolution of the 4X4. We entered the era of all-wheel-drive vehicle control systems when they became more sophisticated.

AWD is optimized for high-speed and all-weather performance and not necessarily intended for off-road. The basics parallel 4X4 with full-time (all wheels engaged) and part-time systems (where the axle disconnects, so the car is 2WD until 4WD is warranted). Most manufacturers use the part-time system for one simple reason – fuel economy. Additional drive wheels create more parasitic drag, which increases fuel consumption.

Advancements in computer technology allow precise control over the AWD system. The vehicle’s various sensors determine when extra power is warranted. Within milliseconds, the transfer case engages and torque is delivered to the other wheels.

Engineers further program these systems to operate all wheels in specific conditions, such as temperatures below freezing or rain. Performance-oriented vehicles engage the AWD in “sport” mode, allowing optimal take-off traction.

Subaru’s Symmetrical AWD

An exception to the rule above is Subaru’s Symmetrical AWD system. Mounted inline, Subaru’s All-Wheel Drive provides a transfer of torque with minimal drag and power loss. This system does not rely on sophisticated electronic components to engage; adding to the reliability of this full-time AWD setup.

Subaru’s Symmetrical AWD system. Photo courtesy of subaru-global.com

Locking Differentials and 2WD Capability

Do you need a four-wheel drive vehicle? Let’s look at a twist ditch scenario. When one wheel is off the ground, it freely spins since power travels the path of least resistance. Is the truck stuck? Not if equipped with a locking differential. Locking differentials, such as the “Eaton G80” will lock the axles together. This allows up to 100% of the available torque to be directed to the wheel that needs it. The downside to “lockers” is that they suffer around turns and on icy conditions since they cannot adapt for the rotational differences.

Twist ditch designed to showcase the advantage of a locking rear differential. An automatic locking differential “locks”; shifting the power to the wheel that is on the ground. This 2WD truck’s capability increases.

A second option is a limited slip differential. Limited slip differentials improve 2WD performance, just as they enhance 4WD performance. Since they don’t lock, limited slips provide better on-road performance, but in a real tough situation, such as this ditch, could leave you stuck.

Cutaway of the newly re-designed 2019 Ram 3500. Pickup trucks are designed to be multi-purpose. To strike a balance between off-road, towing, and general-purpose use, most utilize a combination of options such as locking rear differentials in addition to 4WD options.

Select-a-Terrain

The next best thing to “there’s an App for that,” is there’s a button for that! Traction control has become an art these days. The systems are so sensitive and quick to react that manufacturers have developed ways to tweak the algorithms to assist you in a variety of situations further.

“There’s a button for that!” Tailored traction management at the flick of a switch! This photo shows what the Jeep Grand Cherokee’s looks like. Many manufacturers incorporate such systems in their off-road machines. Photo courtesy of WK2Jeeps.com.

Using Jeep as an example, the Select-Terrain System manages traction to give you all-weather capability in four modes: Auto, Snow, Sport, and Sand/Mud. The Trailhawk models take it a step further with a Rock mode. While there are many variations based on model and options, here’s a basic run-down on what happens with each setting, using a Jeep Grand Cherokee as the example:

Auto

This is the default mode. The front wheels receive 45% of the power, while 55% is sent to the rear.

Snow

The transmission starts off in 2nd gear, and more torque is sent to the front wheels.

Rock

Only selectable in Low Range, this setting will give you the maximum traction for those low speed, technical obstacles. On the Grand Cherokee, it also raises the air suspension 4 inches

Sand/Mud

Similar to snow mode, but the transmission starts off in 1st gear. More torque is sent to the front wheels.

Sport

This mode biases the rear wheels, up to 80%, for a more sports-car-like feel. The traction control is turned off, and the air suspension lowered. The transmission will shift quicker, as well.

Now Jeep is not the only one with a trick selectable traction management system. Many others are incorporating fun at the push of a button!

What Makes for a Great Off-Road Machine?

The fender of virtually any new Jeep wears a “Trail Rated” badge. Jeep introduced this designation in 2004 models to promote their vehicle’s off-road performance. While Jeep does own the trademark on the term, they use the Nevada Auto Testing Center to test their models in places like Northern Michigan, and actually drive them over the Rubicon Trail, a 22-mile-long route that’s part road and part 4X4 trail over the top of the Sierra Nevada.

Jeep tests the vehicles for their trail worthiness based on five categories – traction, water fording, maneuverability, articulation, and ground clearance. It’s a worthy concept for rating a 4X4 or AWD vehicle. So let’s break these terms down. You can use these as guidelines for gauging what you think you’ll need for your adventures.

Traction

Traction, the central theme of this article, is the ability to keep you on your intended path. Four-wheel drive optimizes traction. Electronic systems such as traction control, stability control, roll-over mitigation and ABS further enhance traction abilities.

A Chevy Silverado kicks up some dust, as the traction control devices, both mechanical and electronic, keep the truck on its intended path.

Water Fording

Water Fording is the ability to traverse across water without taking it in or damaging the engine. Off-road vehicles utilize better weather sealing, and they position electrical connections and air intakes higher to enable driving across a body of water up to 19″ deep. This changes with additional options such as a lift, or a snorkel. The 19″ depth serves as the base requirement to earn this endorsement.

A Jeep Wrangler is showcasing its water fording capabilities. Photo courtesy of Jeep.

Maneuverability

Maneuverability is the ability to safely navigate terrain, dodge obstacles, or pass through narrow gaps. Relevant factors include a shorter wheelbase, tight turning radius, and precision steering.

Maneuverability allows for this Jeep to navigate along the cliffside in Death Valley confidently.

Articulation

Articulation refers to suspension flexibility and the vehicle’s ability to keep stable address when one or more wheel is off the ground. Ground clearance and suspension travel are essential here. Specific models, such as the Jeep Rubicon, incorporate a disconnecting sway bar allowing additional suspension travel.

Chevy Silverado 1500 navigating an off-road course. Notice how much the suspension travels, allowing the truck to stay on the trail.

Ground Clearance

Ground Clearance is the ability to drive over rough terrain and rocks without damage. The angle of approach, break-over, and departure angles are maximized in off-road vehicles. Underbody skid-plating further protect critical components.

The approach angle, break-over, and departure angle for the Jeep Wrangler Rubicon.
Courtesy of motoraty.com.

Beyond 4WD – Tires!

Often overlooked are tire choice and tire wear. Both subjects are incredibly important. These rubber components transfer power to the ground and move you. They are the only things sitting between you and the road. All the traction devices in the world mean nothing if the vehicle is riding on improper or bald tires.

Tire Application Choices

Specific tire applications use different compounds and tread patterns. Summer, Winter, All-Season, and All-Terrain are just a few of the choices. When looking for tires for your 4X4, you might want to determine the most extreme conditions that you will be driving through and pick tires to match.

Summer vs. All-Season

Summer tires should more accurately be called “three-season tires.” If you live in a climate that gets colder weather and you plan on using the same tires year-round, then a summer tire is not going to be a good choice. You may want an All-Season tire. You can tell if your tires are rated for All-Season by the “A/S” designation molded into the tire sidewall.

Winter Tires

For winter driving, the softer compounds and deeper grooves found in snow tires perform well in low temperature, low traction situations. This increases the contact patch of the tire to the road surface. A 2WD car equipped with snow tires can outperform a 4X4 or an AWD car with summer performance tires, which illustrates the power of proper tire choice.

Proper tire choice is key to any driving adventure. Photo courtesy of wallacechev.com

Winter tires are marked with the “Mud and Snow” designation “M+S” or they have the newer “Mountain/Snowflake” symbol. Like the A/S All-season mark, these symbols are molded into the sidewall of the tire. In some areas of North America, Mountain/Snowflake rated tires are mandatory for winter months.

I can vouch for how well winter tires work. The snow tire equipped Eagle Talon pictured at the top of this article, coupled with AWD, was an absolute tank. I should have never sold it.

All Terrain Tires

If you are going to be taking your 4X4 off-road, you want a tire that’s going to hold up to the wear and tear of driving over rocks or through sand. Not all Mountain/Snowflake rated tires should be used during summer months as the rubber compound is too soft for summer temperatures. Some like the BFGoodrich All-Terrain T/A KO2 tire can endure year-round service. It’s got an aggressive tread, protruding sidewall rubber blocks, and a rubber compound designed for both all-season road driving, off-roading, and overland travel.

Rock Crawling

If you plan on doing some low-speed rock crawling, you’re going to want some off-road maximum traction tires. And you’re getting beyond the scope of this article!

Tire Wear and Age

Worn tires significantly decrease stopping distance, traction, and cornering performance. The age of a tire matters, too. Rubber degrades over time and causes tires to crack and split, thus increasing the chance of failure.

Cracks in the rubber of worn tires. These cracks increase your chances of a tire failure. Photo courtesy of CarGurus.com

For those of us who travel into cell phone dead-zones, the last thing you want is to get stranded! When checking tires, do not forget the spare! If going off-road, having a spare tire in good condition could mean the difference between getting home safely or not.

Easy guide to checking tire wear. At 4/32″ of wear, you should consider a new set of tires. Photo courtesy of utires.com

What Does This Mean for Photographers?

From the mundane daily commute to save-your-hide-in-sticky-situation drives, modern cars are engineering marvels. Honestly, most of us do not need a Four-Wheel Drive or All-Wheel Drive car.

However, for those considering modest off-road thrills, the assurance AWD and 4X4 offers you is undeniable. Any of the smaller SUV’s, and cars like Subarus, provide the capability needed for the average groomed trails. For those adventurers who want to travel overland on backcountry trails in slick rock country or climb mountains, that Jeep Wrangler with the Rock-Track 4X4 system is waiting for you. Go scale that mountain and snag that Milky Way badge!

To read more about various aspects of four-wheel drive systems, check out the following web sites:

Jeep Trail Rated

Subaru AWD Drivetrain

Eaton Differentials and Traction Control Systems

Nevada Automotive Test Center

BF Goodrich Tires All Terrain T/A KO2

If you have any question, you can either comment below or make a post in our Community Forum.

9 COMMENTS

    • Glad you liked it!
      It wasn’t until recently where I was like, “man I wish I had more ground clearance!”. And thus sparked the idea for this article. That, and looking back on conversations I’ve had at shows. We often overlook our trusty photography steeds! 🙂

  1. I bought a Grand Cherokee in ’95 just so I could get to less travelled places. My ’90 Jetta did an amazing job before that getting me around, but one road from the Colorado up to Dead Horse Point and another above Silverton in Colorado’s San Juan’s convinced me I need AWD on the first road and more clearance for the second road. I ended up with a fist-sized dent in the oil pan and was lucky it didn’t puncture it! I made sure the Jeep csme with skid-plates under it after that experience!

  2. Great article, Marybeth! I literally just finished my search for a new “adventure-mobile.” Was all set to grab a Toyota 4Runner but then I sat my wife and two young kids in it and spent some time driving. It’s not the greatest “family hauler,” and it’s loud as all get-out inside the cabin as well. Compromised a bit on the off-road capability and bought a 2019 Subaru Ascent. It’s got clearance to handle some pretty serious terrain, but also handles like a car and is quiet as a luxury sedan inside!

  3. I want a pick up… It needs 4 doors and off roading capability… And, I believe I want to be able to pull a 5th wheel. But, I am not sure. I have owned two 2500 HD’s and loved them. Both Duramaxes. But, I am looking at used trucks now and Kinda am tempted by a two to three year old Raptor. I want to put a cap on the bed, some pull out drawers. And I want to put a rooftop hard top Baroud type camping pop up on it. And… I want to do it all cheap.

    • LOL, I hear ya… I always want to do things cheap! I’ve been watching the upcoming Jeep Gladiator. That’s a true Jeep with truck capability, including 7,650 lbs of towing. Although you can’t do 5th wheel with that, it can do smaller trailers and even cars. Of course, I always buy things used and would have to wait a few years – again, because #cheap.

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