AGRICULTURAL TYRES · JUNE 2025
Flotation tyres for tractors are one of the most misunderstood investments in UK farming. This guide cuts through the noise — covering how they work, what the numbers actually mean, and how to choose the right flotation wheels and tyres for your operation and soil type.
Soil compaction costs UK arable farmers an estimated £250 million in lost yield every year. Some of that is unavoidable. A significant portion of it is a direct consequence of running the wrong tyres at the wrong pressure for the conditions — and it shows up not this season, but two or three years down the line when rooting depth drops and drainage starts to fail.
Flotation tyres exist to solve one specific problem: spreading the weight of a heavy machine across a larger contact patch so less pressure goes into the ground. The physics is simple. The options are not — because getting it right means understanding your tractor's weight, your axle loads, your soil type, and which combination of width, diameter, and inflation pressure delivers the ground contact you actually need.
This guide covers everything a UK farmer or contractor needs to know about flotation tyres — what they are, how they work, how to size them correctly, and what to look for when choosing between standard and IF/VF technology.
What Are Flotation Tyres?
Flotation tyres are wide-section agricultural tyres designed to reduce ground pressure by distributing a machine's weight over a larger footprint. Rather than concentrating load onto a narrow, high-pressure contact patch, a flotation tyre spreads that same load across a broader, flatter area — reducing the pounds per square inch (psi) pressing into the soil.
The term "flotation" refers to the tyre's ability to carry heavy loads over soft, wet, or sensitive ground without sinking — the same principle used in snowshoes or tank tracks. In an agricultural context, this means less rutting, less subsoil compaction, and better crop establishment the following season.
"The question isn't whether your soil is being compacted. It's whether your tyres are making it worse than it needs to be."
Flotation tyres are typically fitted to rear axles, trailers, slurry tankers, spreaders, and combine harvesters — any machine where high axle loads are unavoidable. They are also increasingly specified on front axles of large four-wheel drive tractors running heavy front-mounted implements. View the full flotation wheel range for paired wheel and tyre options across all common axle configurations.
Typical Ground Contact Pressure — Common Agricultural Tyres
Approximate values at recommended inflation pressures — lower is better for soil health
Flotation Wheels and Tyres: Understanding the Full System
A flotation tyre fitted to the wrong wheel is a compromise at best and a safety issue at worst. Flotation wheels and tyres work as a system — the rim width, offset, and load rating of the wheel must be matched to the section width and load index of the tyre. Running a wide flotation tyre on a narrow rim forces the sidewalls inward, defeats the purpose of a wide contact patch, and accelerates sidewall wear.
As a rule of thumb, rim width should be 70–75% of the tyre's section width. A 600mm section tyre typically requires a rim in the 16"–20" width range depending on the specific tyre specification. Always confirm rim compatibility with the tyre manufacturer before ordering — and check our flotation wheel range for paired options sized and rated for the most common UK agricultural applications.
| Factor | Flotation Setup | Standard Setup |
|---|---|---|
| Ground contact area | Very large — spreads load wide and flat | Smaller — concentrates load in narrower patch |
| Inflation pressure | Low (0.5–1.0 bar typical at field speeds) | Higher (1.2–2.0 bar typical) |
| Soil compaction risk | Significantly lower — especially on wet soils | Higher — particularly in autumn harvest conditions |
| Road suitability | Good — pressure raised for road transport | Good at standard pressures |
| Initial cost | Higher — offset over time by yield protection | Lower upfront, higher long-term soil cost |
| Best application | Trailers, slurry tankers, combines, heavy rear axles | Lighter field operations, dry conditions |
IF and VF Technology: What the Letters Mean in Practice
Improved Flexion (IF) and Very High Flexion (VF) tyres represent the current benchmark in flotation tyre technology for UK agriculture. Both use reinforced, flexible sidewall construction to carry the same loads as a standard tyre at significantly lower inflation pressures — without the risk of sidewall failure that would come from simply under-inflating a conventional tyre.
IF tyres can carry standard loads at 20% lower inflation pressure. VF tyres go further — 40% lower pressure for the same rated load. In practical terms on a 10-tonne axle load, that difference translates to a contact patch roughly 30–35% larger, and ground pressure reduced from around 1.2 bar to as low as 0.7 bar depending on the tyre size selected.
The key point for UK farmers is that IF/VF flotation tyres for tractors are not a premium luxury item — they are an engineering response to a specific agronomic problem. On heavy clay soils in autumn, a 12-tonne slurry tanker fitted with standard tyres at road pressure will compact the subsoil to a depth that takes years to recover. The same tanker on VF flotation tyres at field pressure keeps the damage in the topsoil layer, which earthworm activity and freeze-thaw cycling can address within a single season.
A contractor running a 14-tonne combine with a loaded grain cart alongside it on standard tyres in a wet October is applying ground pressure well above 1.5 bar on every pass. That's not an issue in dry conditions — but in the wet seasons the UK regularly delivers, each pass is compacting soil to a depth where conventional cultivations won't reach it. Switching to flotation tyres for tractors and carts doesn't eliminate the problem, but it reduces subsoil pressure to levels that are recoverable within the normal cropping cycle.
How to Size Flotation Tyres Correctly for Your Operation
Tyre sizing starts with axle load — not tyre width. The most common mistake is selecting a flotation tyre by width alone, then discovering it can't carry the rated axle weight at the inflation pressure needed for your soil conditions. The correct sequence is: establish your maximum axle load, determine the target ground pressure for your soil type, then identify which tyre size and technology delivers that combination.
Every tyre manufacturer publishes load/inflation tables — the relationship between tyre inflation pressure and the maximum load the tyre can safely carry at a given speed. For field operations (typically below 10 km/h), many tyres are permitted to run at higher loads than their road rating, which is where IF and VF designations become significant — they extend this capacity further while keeping pressure low.
For a more detailed breakdown of how axle loads, tyre section widths, and inflation pressures interact on UK soils, see our ground pressure and tyre sizing guide — it covers clay, sandy loam, peat, and chalk soils separately, with worked examples for common trailer and tractor configurations.
"Establish your maximum axle load first. Then work backwards to the tyre. Not the other way around."
For rear axles on modern large tractors (200hp+), tyre widths of 600–650mm are the practical range for most UK applications. For trailers and tankers, 550–710mm widths are common, with single or twin configurations depending on load rating requirements and track width restrictions. Twin tyres on trailers effectively double the contact area but also double the track width — check your headlands and gateways before specifying.
CTIS (Central Tyre Inflation Systems) are increasingly worth considering alongside flotation tyre investment. CTIS allows the driver to adjust tyre pressure from the cab — running at higher road pressure for transport and dropping to optimal field pressure automatically before entering the field. The system removes the barrier of stopping to manually adjust pressures, which in practice means it actually gets used. Without CTIS, even correctly sized flotation tyres are frequently run at road pressure in the field because stopping to deflate takes time nobody has at harvest.
Flotation Tyres for Specific UK Agricultural Applications
Not every machine benefits equally from flotation tyres — and the specification should reflect the actual use case. Here is how flotation tyre requirements vary across the most common UK agricultural machinery:
Slurry tankers and vacuum tankers carry some of the highest axle loads of any machinery entering a cropped field — often 10–14 tonnes per axle when full. This is the single application where flotation tyre specification makes the biggest difference to soil health outcomes. Wide VF or IF tyres at correct field inflation pressure can keep surface pressure below 1.0 bar even at these extreme loads. Running a loaded tanker on standard tyres at road pressure on wet ground is one of the fastest ways to create compaction damage that requires subsoiling to correct.
Combine harvesters — particularly modern large-capacity machines with full grain tanks and header attached — can exceed 30 tonnes in total weight. The rear axle in particular carries a disproportionate share of this load. Factory-fit tyre options on combines have improved significantly, but many operators still fit aftermarket flotation upgrades to rear axle positions in recognition of the conditions UK harvests regularly deliver.
Grain trailers and silage trailers running at legal road weights (up to 24 tonnes GVW for a single trailer) present a real-world tension between road pressure requirements and field pressure targets. A twin-axle trailer at full load running at 3.0 bar for the road journey and then entering a field without dropping pressure is applying enormous compaction force. Flotation tyres help — but only if the pressure is actually adjusted.
Crop sprayers are the application where the flotation tyre argument is most clear-cut. A self-propelled sprayer with full water load makes dozens of passes across a single field. Even small reductions in ground pressure per pass compound across the season. Wide flotation tyres on sprayers — often in the 600–650mm range — are now standard specification on most machines above 24m boom width, and the soil science firmly supports the investment.
Explore the full range of agricultural tyre options — including standard radials, IF and VF flotation tyres, and specialist harvest tyres — with load and inflation data for each size. For sizing guidance specific to your machine and soil type, use our ground pressure and tyre sizing guide.
The True Cost of Getting Flotation Tyre Specification Wrong
The argument for flotation tyres is often framed around compaction prevention — but the economic case is more immediate than that framing implies. Let's make this concrete.
A 200-hectare arable farm running a 10-tonne trailer with standard tyres through a wet autumn is compacting approximately 15% of its arable area per year to a depth that limits root development. At current UK wheat yields and prices, a 10% yield reduction on that 15% of the farm area represents a loss of around £8,000–£12,000 per season — not counting the cost of subsoiling to correct it (typically £25–£35 per hectare), which adds another £750–£1,050 per year if the compacted area requires remediation.
A set of wide flotation tyres for a 10-tonne trailer costs £2,000–£4,000 depending on specification. The payback period, on these numbers, is less than a single season. That is not a speculative claim — it is the arithmetic of soil compaction cost, and it is why the UK's most productive arable farms have been specifying flotation across their trailer and tanker fleets for over a decade.
Subsoil compaction below 35cm typically cannot be corrected by any cultivation method short of deep loosening at £60–£80 per hectare. If a single wet harvest creates compaction at that depth across 30 hectares of your most productive ground, the remediation bill alone exceeds the cost of correctly specified flotation tyres on every machine in your fleet.
Key Questions to Ask Before Buying Flotation Tyres
Before specifying flotation tyres, work through these questions with your tyre supplier:
What is my actual axle load — not the theoretical maximum? Weigh the machine in typical working condition. Many farmers are surprised to find their actual axle loads significantly above what the machine handbook suggests once implements, water ballast, and grain are accounted for.
What is the dominant soil type on my worst-performing fields? Heavy clay at field capacity needs ground pressure below 0.8 bar to avoid subsoil compaction. Sandy loam in summer can tolerate significantly more. Your tyre specification should be driven by your most sensitive conditions, not your average conditions.
Is IF or VF technology justified by the axle load? IF and VF tyres cost more. If your axle loads are moderate and you are operating on well-structured soils, a wider standard radial at correctly reduced pressure may deliver acceptable ground pressure without the premium. If you are carrying 10+ tonnes per axle on clay in autumn, VF is almost certainly justified.
Will I actually adjust the pressure? A CTIS-equipped flotation tyre delivers real benefits. A flotation tyre run permanently at road pressure delivers almost none. Be honest about operational practice before investing in the most expensive tyre option.
The right flotation tyre specification protects yield, reduces remediation cost, and extends the productive life of your soil. The wrong one — or the right one at the wrong pressure — does neither. If you are unsure where to start, the question to answer is simple: what is the heaviest machine entering my most sensitive fields in the wettest conditions, and what ground pressure is it delivering right now?
Browse the full flotation wheel range and agricultural tyre options, or use the ground pressure and tyre sizing guide to work through your specific machine configuration.