True: Tracks offer better flotation than tires, especially in mucky field conditions. But are tracks also better than tires at avoiding compaction? Not exactly. So which one is better—tracks or tires? As with many decisions in agriculture, the right answer isn’t black and white. When it comes to compaction, tires can actually perform better than tracks. And with advancements in tire technology, such as IF- and VF-rated radials, tires may bring you benefits that tracks can’t touch. Let’s review some facts about tracks and tires to see where each stands on the specific issue of compaction.
Tracks: The Choice for Finishing Fieldwork at All Costs
There’s no question that tracks provide superior flotation when driving across stubbornly wet fields. This is because a track’s lugs are “planted” in the soil and push the undercarriage (and tractor) forward, which generally means no ruts and better traction in wet soils when compared to standard farm radials. Tires, on the other hand, create a wave of soil as they rotate. As the tractor moves forward, it is constantly climbing out of its own ruts. When farmers decide to run tracks, flotation and maximum grip are the top two reasons they list.
And this is why tracks are so popular on harvesting and tillage tractors: When you need to get your crop out and work your ground at all costs, flotation and traction in wet, sticky soils is a priority. In addition to the grip that tracks offer, many farmers prefer them because:
- There are no tire pressures to check or adjust based on the application and load.
- There is no power hop or road lope to contend with.
- Track machines are generally narrower than large dual setups. This is valuable whether you have to navigate narrow, twisty township roads or even wide state highways: you should never underestimate the average driver’s ability to run into just about anything, including your tractor.
Tracks: Plenty of Reasons to Think Twice
However, tracks come with some notable drawbacks. And with the advancements in radial tire technology, any one of these drawbacks may be the pain point that pushes a farmer to stick with tires or switch back to them.
- Compaction: Track machines are generally 20–30% heavier out of the gate, which increases your risk of causing harmful deep soil compaction. While a track’s extra flotation helps with compaction close to the soil’s surface, the depth of compaction in the soil is always a function of axle weight. The heavier your machine is, the deeper you’re driving compaction. Plus, as you’ll read below, the pressure a track puts on the soil isn’t evenly distributed across its entire footprint.
- Higher Fuel Bill: Tracks have to bend in a tight radius at least twice around a driveline component. And considering how stiff tracks are, thanks to their substantial cable and belt packages, just moving the tractor forward requires more fuel than its wheeled counterpart. This results in a higher fuel bill and also means that there’s actually less power on board to pull the implement. Field testing of John Deere 9620R and 9620RX tractors showed the wheeled tractor consuming approximately 15 percent less fuel than the track tractor.
- Slower Roading: Because of their stout construction and necessary resistance to bending and stretching, tracks also generate a lot of heat at road speeds. While some track machines can run 25 mph with the right tracks, many farmers still have to deal with restricted road speeds. The more road travel you do between fields, the more this will end up decreasing your productivity.
Sticker Shock: Yes, track machines are more expensive than wheeled versions up front. But you also have to think about the maintenance issues that will creep up on you over the machine’s life: midroller and idler wheel replacements, bad seals, multiple grease points, and more.
Tires: Winning the Compaction Battle
While it’s true that tracks “float” better than tires, they don’t necessarily offer lower soil compaction levels when compared to tires. Why not? Because the tractor’s load is concentrated on the areas of the track beneath its idler and bogie wheels. In other words, tracks don’t distribute the tractor’s weight evenly across their footprints. A Tekscan™ measuring more than 100,000 data points recorded the 9620R wheel tractor having a 16 percent lower average pressure and a 38 percent lower maximum pressure than the 9620RX track tractor.
The image and chart above show the high pressure points under each midroller. A study conducted by the University of Minnesota found that properly inflated duals will cause less compaction than tracks. Because tires are essentially rolling air chambers, they distribute an implement’s load evenly across their surface area.
As you’ll notice in the above chart, air pressure is vital to maintaining a tire’s compaction edge over its track competition. Outfitting a heavy tractor with tires that can run on lower air pressures (and adjusting your tire pressure for specific applications) will help prevent yield-killing compaction. In the study above, 6 and 7 PSI (front and rear respectively) was the optimal tire pressure for the 710/70R38 duals. The "overinflated duals" were set to 24 PSI.
The Best Tires to Limit Compaction
Radial tires exert a pressure on the soil that is 1 to 2 pounds greater than their inflation pressures. The lower you can keep your inflation pressure in the field, the better off your topsoil will be. This is where IF/VF tires come into play. IF (increased flexion) and VF (very increased flexion) radials have closed the gap with tracks when it comes to traction and flotation. First launched by Michelin in the early 2000s, this tire technology has been on the ground for a while now and has proven to be a game changer.
How do these tires work? IF/VF radials put more tire—a larger footprint—on the ground thanks to lower air pressures and more sidewall flex.
- IF radials can carry the same load as a standard radial at 20% less pressure.
- VF radials can carry the same load as a standard radial at 40% less pressure.
- Or, you can increase their maximum loads by 20% or 40% above a standard radial’s limits.
From these footprint maps, it’s easy to see how a tire’s footprint grows as you drop the air pressure. Plus, when your tires put down a larger footprint, you also get more lugs on the ground which means better traction. Often, this traction increase is enough to boost efficiency: decrease slip and you’ll be able to work faster while burning less fuel.
Minimize Compaction and Maximize Fuel Efficiency with a Central Tire Inflation System
Here’s a problem with tires: There is no one correct tire pressure for your tractor. Why? Because your tractor lives in two worlds—the road and the field. For fieldwork, most experts recommend staying below 15 psi if at all possible. Run down the road with tires at your optimized field psi, however, and you’ll slash your tires’ life, burn extra fuel, and deal with mushy handling. On the road, you want your tires as firm as possible. Pick a pressure somewhere in the middle, and your tires aren’t optimized for anything.
The solution is a central tire inflation system. According Michelin, the owner of PTG Tire Inflation Systems, a central tire inflation system can deliver:
NTS Tire Supply Can Help You Increase Machine Performance
At NTS Tire Supply, we know that every farm is unique. However, whether you run tires or tracks or both, your machine’s rubber is its only link to the ground. Whether you’re interested in upgrading to IF/VF radials, you need a replacement set of tracks, or you want to learn if a central tire inflation system will pay off for your operation, our tire experts can offer you unbiased advice. Unsatisfied with your tractor’s performance? Give NTS Tire Supply a call and talk with one of our tire experts. NTS Tire Supply will help you get the right tires, tracks, and air pressure on all your equipment to Drive Your Farm Forward.