Can You Drive in 4wd High on the Highway? Answers & Advice

Using four-wheel drive (4wd) can provide traction and control in low grip situations like snow, mud, or off-road. But is it safe and recommended to drive in 4wd high (4h) at highway speeds on dry pavement?

In this detailed guide, we’ll cover when and how to use 4wd modes properly, including 2wd, 4h and 4l. Read on to learn the top tips for operating 4×4 vehicles on highways and in different conditions to avoid damage and maximize performance.

What is 4wd and When is it Needed?

Four-wheel drive, also known as 4wd or 4×4, refers to a vehicle drivetrain that can distribute power to all four wheels for additional traction. This is in contrast to rear-wheel drive (RWD) or front-wheel drive (FWD) cars that only power two wheels.

In normal driving conditions on dry pavement, two-wheel drive is perfectly adequate for daily transportation. However, 4wd has key advantages in situations with reduced traction, such as:

• Driving in snow, ice or heavy rain where wheels can lose grip
• Off-road driving on loose or slippery surfaces like mud, dirt, gravel or sand
• Driving up or down steep and uneven terrain
• Pulling heavy loads where extra traction helps
• Improved control in emergency maneuvers

By allowing some power transfer between front and rear axles using a center differential, 4wd allows continued momentum even if one set of wheels loses traction. This is a major improvement compared to 2wd vehicles which can become immobilized when only one set of drive wheels slips.

The downsides of 4wd are slightly more complex drivetrain, added weight, and reduced fuel economy compared to 2wd. But for specific applications like off-roading or winter driving, the benefits are well worth it.

Now that you understand what 4wd does and when it helps, let’s cover the specifics of how to use it properly on and off pavement.

Is it Ok to Drive in 4wd on Dry Pavement?

Many people think you should only engage 4wd when you’re off-road or on slippery surfaces. But is it actually bad for the drivetrain to use it on dry pavement?

The answer is that in most cases, it is perfectly fine to drive in 4wd on dry roads. Since all four wheels receive at least some power, the drivetrain components share the load and don’t experience abnormal wear.

The exceptions are situations like tight turns from a stop where 4wd engagement could bind up the drivetrain. To avoid this, just switch back to 2wd for any tight turns.

Here are some examples where using 4wd on dry pavement can be beneficial:

• Improved traction when towing or hauling a heavy load uphill
• Braking enhancement on steep declines
• Better grip at highway speeds in very windy conditions
• Extra control in heavy rain when hydroplaning risks increase

Just be sure to refer to your owner’s manual, as a small number of 4wd systems do specify 2wd only for dry pavement. But in general, don’t be afraid to engage 4wd if the conditions call for it.

What are the Different 4wd Modes?

Most 4wd vehicles have a transfer case that allows switching between different modes depending on the conditions:

2wd (2h) – Power only goes to the rear wheels, like in a standard RWD vehicle. Fuel economy is maximized in this setting.

4wd High (4h) – Power goes to both axles but gearing remains unchanged. This maintains normal on-road performance while still providing 4wd capabilities.

4wd Low (4l) – Power goes to all four wheels and gearing is reduced for low-speed off-road use. 4l provides maximum traction but limits speed.

The ability to shift between these modes provides the versatility to operate the vehicle efficiently. You can engage 4wd for specific situations that require it, then disengage when no longer needed.

Here are some guidelines for when to use each mode:

• 2wd – Normal dry pavement driving for best mpg.
• 4h – Slippery roads, light off-road,heavy hauling/towing, windy conditions.
• 4l – Heavy off-road use, steep terrain, deep snow/mud, rock crawling.

Refer to your owner’s manual for full instructions on when and how to operate the different 4wd settings. With practice, choosing the right mode will become second nature.

Is Driving Above 70 mph Safe in 4h Mode?

Unlike 4wd low range which has clear speed limits, 4wd high does not technically have a top speed cap on most vehicles. But just because you can go over 70mph in 4h doesn’t necessarily mean you should.

Here are some important factors to keep in mind:

• Increased drivetrain wear – At highway speeds, the 4wd system experiences far more rotational force than normal operation. This puts more stress on components like differentials, transfer case, driveshafts, etc.
• Reduced maneuverability – Above 55-65 mph the front wheels can lose traction limits, reducing steering responsiveness.
• Decreased stability – The higher center of gravity of 4wd trucks already reduces stability at speed. Engaging 4wd further raises the risk of rollovers or loss of control.
• Limited braking – 4wd on dry roads lessens rotational differences between front and rear wheels, reducing maximum braking force potential.
• Driver discomfort – On the highway, 4wd engagement can cause unexpected vibration and noise.

For these reasons, it’s recommended to drive at moderate speeds below 65 mph whenever using 4h mode. Reserve 4wd for lower speed backroads where the benefits outweigh the tradeoffs. Let’s look closer at highway use cases next.

Should You Drive in 4h on Dry Highways?

Given the factors above, here are some guidelines regarding using 4wd on dry highways:

• Avoid prolonged use – Don’t make a habit of regular highway commuting in 4h when not necessary. The added drivetrain wear accumulates over time.
• Check owner’s manual – Some vehicles specifically prohibit speeds above 50-60 mph in 4h. Follow all manufacturer instructions.
• Engage only when needed – If driving in rainy or windy highway conditions with reduced grip, 4h can help avoid issues. But switch back to 2wd after the situation improves.
• Turn off for tight turns – As mentioned earlier, disengage 4wd before any low-speed turns to prevent drivetrain bind up. This includes highway off-ramps taken at sharp angles.
• Use 2wd when possible – For normal highway cruising on dry pavement, 2wd maximizes drivetrain longevity and fuel mileage.

In summary, exercise caution with 4h use at highway speeds. Engage only temporarily when conditions warrant extra traction or control. Otherwise, default to 2wd for most on-road driving.

What Speed is Recommended in 4h Mode?

While highway speeds in 4h are possible, the ideal speed range is much lower for optimal 4wd performance and minimum component wear. Here are some general 4h speed guidelines:

• Under 25 mph – 4h engagement generally not needed unless climbing a steep, slippery slope or crawling off-road. Use 2wd for normal conditions.
• 25-45 mph – The ideal range to employ 4h mode for improved traction and control in rain, snow, ice, or light off-road.
• 45-60 mph – Acceptable 4h speed for short durations in poor conditions. But not recommended for prolonged highway use.
• Above 60 mph – Inadvisable speeds in 4h. Risk of drivetrain binding and loss of control increases substantially above 55 mph.

As always, check your owner’s manual for the maximum recommended speeds in 4h. Most specify a top limit around 60 mph, with some as low as 50 mph. Consider installing added gauges to monitor vital stats like transmission temperature when operating near the limits.

Maintaining reasonable 4wd high speeds avoids potential damage while still allowing you to benefit from the improved traction. Now let’s look at another concern – increased drivetrain stress in 4h.

Does Driving in 4h Put More Stress on the Drivetrain?

Engaging both axles to power all four wheels does fundamentally change how the engine torque is distributed throughout the drivetrain. This has several effects:

• Increased loading – With 4wd, all driveline components share the engine power rather than just the rear axle. This distributes but also multiplies the stress.
• Extra rotational forces – The front and rear driveline sections are rotating at various speeds based on conditions, creating internal binding forces.
• Heat generation – Greater friction from the increased loading and rotation creates more heat at higher speeds.
• Power wind-up – Attempting to switch between 2wd and 4wd while moving can wind up the drivetrain from differences in front/rear wheel rotation.

The low range gears in 4L provide tremendous mechanical advantage but also maximize drivetrain torque. 4H is more moderate but still adds significant stress versus 2wd.

Does this mean you should avoid 4wd to prevent premature wear? Not necessarily. By using it judiciously and keeping highway speeds reasonable, you can benefit from 4wd while minimizing the risks of damage.

Proper driving technique makes a big difference. Next we’ll go over some best practices for engaging and disengaging 4wd.

When Should You Engage and Disengage 4wd?

Shifting between 2wd and 4wd modes is a key advantage of 4wd vehicles. But for maximum longevity, be strategic about when you switch in and out of 4wd:

On pavement

• Engage proactively when traction seems marginal – don’t wait for wheels to slip.
• Disengage once conditions improve and grip returns to normal.
• Avoid tight turns and U-turns in 4wd to prevent driveline binding.

Off-road

• Engage 4wd before reaching the loose surface if possible.
• Stay in 4wd until completely back on solid ground.
• Use 4L for rocky, steep, or obstacle-strewn terrain.

General tips

• Make shifts while either stopped or below 45 mph.
• Move the selector smoothly and decisively between modes.
• Wait briefly for the switch to fully engage before accelerating.
• Refer to dash indicators and listen for engagement sounds.
• Err on the side of early 4wd activation rather than waiting until slippage occurs.

Follow those guidelines and you’ll develop good 4wd engagement instincts. Next let’s cover another common question – using 4wd in the snow.

Is 4wd Necessary for Driving in Snow?

Snow-covered or icy roads present one of the biggest challenges for maintaining grip. The loss of traction also impairs steering control and braking effectiveness.

For this reason, 4wd is highly recommended for winter driving conditions. Here are some of the advantages:

Improved acceleration – Applying power to all four wheels keeps you moving without wheel spin. This helps you get started as well as climb inclines.

Enhanced steering – With all four corners pulling, you can turn more easily through deep snow without losing momentum.

Better braking – 4wd allows all wheels to contribute to slowing and stopping power, cutting braking distance.

Increased stability – The firmly planted stance with 4wd activated reduces risk of fishtailing or spin outs.

Traction uphill – Climbing steep and slippery hills is extremely difficult in 2wd vehicles. 4wd helps avoid getting stuck.

Peace of mind – Overall confidence and capability to handle unexpected situations is greatly improved with 4wd.

For best results, be sure to use proper winter tires and drive cautiously. But having 4wd can make winter driving much safer and less stressful.

Now that you know the major benefits of 4wd for snow and ice, let’s look at some typical 4wd-equipped vehicles.

What Types of Vehicles Normally Have 4-Wheel Drive?

While any vehicle can be equipped with 4wd, it most commonly comes standard or as an option on SUVs and trucks. Here are some examples grouped by brand:

Jeep – Wrangler, Grand Cherokee, Cherokee, Compass, Renegade

Toyota – 4Runner, Tacoma, Tundra, Land Cruiser, Sequoia

Ford – F-150, Ranger, Expedition, Explorer, Escape, Bronco

Chevrolet – Silverado, Colorado, Tahoe, Suburban, Trax, Equinox

Dodge – Ram trucks, Durango, Journey, Charger

Nissan – Titan, Frontier, Pathfinder, Xterra, Armada

Subaru – Outback, Forester, Crosstrek, Ascent

You’ll notice most 4wd models are larger SUVs or pickups. But some crossover SUVs and even sports sedans like the Dodge Charger also offer 4wd variants. The specific capabilities and recommended use can vary between 4wd systems too. So consult your owner’s manual for specifics.

With the right tires and careful operation, virtually any properly equipped 4wd vehicle can confidently handle moderate snow and off-road use. Understanding how to optimally employ the different 4wd modes is key to maximizing performance and longevity.

Conclusion – Smart Use of 4wd Modes Matters

We’ve covered a lot of ground explaining how 4wd works, when to engage it, recommended speeds, and real-world use cases. Here are the key takeaways:

• 4wd improves traction and control in low grip situations like snow, mud, and off-road.
• Use 2wd for normal highway driving and engage 4wd only when needed.
• It’s ok to drive 4wd on dry pavement, just avoid tight turns.
• Optimal 4h speeds are 25-45 mph. Use 2wd above 60 mph when possible.
• 4wd does increase drivetrain stress, so activate judiciously based on current traction.

Remember, you don’t have to be actively slipping to benefit from 4wd. Engage proactively when conditions suggest available grip is reduced. Doing so will provide confidence, safety and potentially prevent getting stuck or losing control.

Now you can hit the road prepared to take advantage of your vehicle’s 4wd capabilities wherever your travels take you! Drive smart and safe out there.