Field Guide - Airing Down Your Tires for the Trail

Rule number one of driving in the dirt is; Air down your tires. One of the simplest and simultaneously most dramatic adjustments to your rig that will improve your trail capabilities is airing down your all terrain tires from highway pressure to trail pressure. A small reduction in air pressure can have a dramatic effect on traction, floatation and the overall trail manners of your truck. Even though the concept of airing down tires for off road driving may seem complicated, the process is simple and the needed equipment to do so is affordable.

Whether you are new to overlanding or already spend any time on trail, you should really consider trying lower tire air pressure to match the conditions. You can greatly improve your traction by adding up to 80% in length and 20% in width to your tire’s contact patch with the ground. When this contact patch increases so does the amount of friction with the ground. Decreasing pressure can often be the difference between crawling over arduous obstacles or wheel spin. While this lower pressure should only be used off road, the benefits while overlanding are numerous.

Benefits of Airing Down Your Tires For the Trail

• Increased traction over roots, rocks, and obstacles
• Better floatation in sand, snow, and mud
• Smoother rides on washboard and small bumps at medium to low speeds
• Sidewall deflection allowing your tire to adapt to rocks roots and other obstacles
  

Smooth rides aren't just for comfort, it provides mechanical sympathy for your rig so you're not just ratteling it to pieces. Your tires along with the bushings are also an integral piece of your vehicles total suspension setup. If you're constantly bumping off the bumps and washboards your tires aren't in contact with the ground meaning you can't stop or steer. Proper tire pressure keeps you better contact with the ground giving you better control. Smoother rides also translate to less fatigue, if you're tired youre more likely to make mistakes, use bad judgement, or just not see something, keeping it smooth means having more fun off road longer into the day while staying safe.

It’s important to understand the benefits of running lower air pressure as well as the limitations and downsides. First off, the lower you go doesn't always mean the better off you are. There is no magic formula to decide what pressure is best to use at a given time or trail. Optimal pressure will differ with seasonal changes, weather, trail conditions, and your vehicle setup but here are some rough guides for a typical mid-size truck.

• 45 - 35psi Pavement
• 25 - 20psi Trails
• 15 - 10psi Sand
• 10 - 2psi Snow / Soft Sand preferably with beadlocks

One way to think about tire pressure is that it’s the pressure your tires are exerting on the supporting surface. For example,sand can’t support as high of pressure, hence why you sink in, and you need to lower the pressure to increase the size of your "footprint" and "float." Most passenger vehicles and medium duty trucks use factory tire pressures between 35 and 45 PSI on the pavement. When hitting the trail, we recommend starting at about 25psi and adjusting from there as necessary. For sand, we start at about 15psi and if it’s still bogging down start dropping it in 2-3psi increments down to an extreme of about 10psi. We don’t recommend going below 10psi unless you are using beadlocks or you are in a rut and need to get unstuck from soft sand or deep snow. If you do air down that low it’s important to take it really easy and air back up as soon as you’re unstuck. As you gain more experience and get comfortable, you’ll start to know what pressure to run and when to adjust on more challenging trails.

Driving Considerations Aired Down Tires

When dropping pressure, it’s critical to be aware of other aspects of your truck that will change.

• Your axle clearance will be slightly reduced as your ride height drops.
• The connection of the tire to rim, known as the bead, will not be holding as tightly.
• Turning sharply into an obstacle can throw a tire’s bead and go flat on the spot.
• Over-aggressive cornering coupled with extremely low pressure can further increase your chances of throwing a bead.
• Your sidewall will be deformed and more vulnerable to being pinched or punchtured on sharp rocks.

If you're running an off-road trailer it’s important to air down its tires too. The optimal trailer tire pressure will keep it from bouncing around on a wash-board forest road or bogging down the tow rig due to the added drag.

Why It's Important To Air Up Your Tires Once Off the Trail

Airing back up before getting back on the pavement and reaching highway speeds is critical. Even a drop in 10psi will considerably change the handling and safety when traveling down the interstate at 70 mph. Ideally, you will air up right before you hit the pavement. It’s a great time for the convoy to gather up on a forest road and double check each other's work and reflect on a great day.

The Right Tools for The Trail

We love the Ironman line of 4x4 accessories. Ironman offers outstanding quality at an accessible price. For airing down, the Ironman Air Champ Smart Deflator has everything we look for in a must-have trail tool. It’s well built, easy to use, and saves you precious time at the trailhead. The key feature is the tire valve core remover built into the deflator. Removing the core allows an increased air flow leaving the tire and the tool retains the core while in use to prevent it getting lost.

When it’s time to air back up to highway pressure, you’ll want to look for a compressor with a high CFM (cubic feet per minute) that connects directly to the battery and ideally a 100% duty cycle. A battery connection is safer for the electrical draw of running a compressor continuously. Some cigarette outlet wirings are not designed to run a higher output accessory like a compressor. We love the Air Champ Pro 5.65cfm - 12v Heavy Duty Portable Air Compressor, again from Ironman. It has all the features to round out your deflate and inflate kit. It’s also a nice upgrade from a lot of the smaller 12v portable compressors out there. Pair it with the Air Champ Dual Inflator and you’ll have your front and rear tires airing up as pairs and their psi perfectly equal.

Airing Down Tools Available from Nomadica

Three pieces of kit that will dramatically improve your off road capability. It would be difficult to find a similar investment that would have a similar improvement to your rig’s overall trail prowess.

Nomadica Outfitters

Nomadica Outfitters is an outdoor equipment store specializing in tools, gear, and apparel to address the challenges presented by remote off-road adventures. Our overland products facilitate simple fast setup, easy stowage, and are built to last - allowing you to spend more time adventuring and less time packing. Be curious, embrace the unexpected, explore, and discover the wonder that is planet earth.