Treading Lightly – How MAN’s 18.340 4×4 with AIR-CTI is Revolutionising Spreading in Tasmania

On a rain-soaked Tasmanian morning, the mist hangs low over Deloraine’s rolling hills, and the waterlogged paddocks glisten momentarily when the sun peeps through the clouds. Most trucks would be parked up, waiting for the ground to firm up. But not today! Yet out in one wet paddock, a MAN TGM 18.340 4×4 fitted with AIR-CTI and a Southern Spreaders bin prowls confidently across the field, tyres barely leaving a mark. We sent our Technical Editor, Howard Shanks, to find out why.

At the wheel is David Cruthers, a man who’s spent a lifetime spreading fertiliser across the north of the state and knows better than anyone how vital it is to tread lightly. With the flick of a switch, he drops tyre pressures from inside the cabin, the big Michelins ballooning out to float across the sodden soil. “This is where CTI earns its keep,” he grins. And in that moment, you realise this truck isn’t just another spreader, it’s a glimpse into the future of more innovative, more sustainable farming.

That truck, a MAN TGM 18.340 4×4, fitted with a Southern Spreaders 750 Chain Contractor unit and equipped with Central Tyre Inflation from AIR-CTI. For Deloraine-based operator Earley Spreading, managed by veteran spreader David Cruthers, this combination is proving to be a game-changer.

“This truck really does tread lightly,” David explains, climbing down from the cab after a long morning in the paddock. “It’s lighter than the competition, more efficient, and thanks to the AIR-CTI, we can run in conditions that would have stopped us dead years ago.”

Waiting for the Rain

When Howard first caught up with David a few weeks before, David suggested holding off on the story until Tasmania’s notoriously fickle weather put the new truck to the ultimate test.

“Wait until we’ve had a decent downpour,” David said with a knowing smile. “That’s when you’ll see what the AIR-CTI system really does, how it protects the soil and keeps us moving.”

Sure enough, three weeks later, the skies opened. Nearly 100mm of rain fell across the north-west. The paddocks glistened with surface water, the soil soft and unforgiving, perfect conditions to see if MAN’s claims of versatility and low-impact running could hold up.

David has spent decades spreading fertiliser across northern Tasmania. He knows the land intimately, where every rock, stump, and tricky slope lies hidden beneath the grass. Alongside Earley Spreading owner Bill Earley, David has long been at the forefront of adopting new technology to give farmers better value.

“Farming is a lot like road transport,” David says. “Margins are tight, efficiency matters, and small improvements can make a huge difference.”

One of the most significant challenges farmers face is soil compaction. Heavy machinery – trucks, tractors, harvesters – pressing down year after year reduces soil porosity, making it harder for roots to penetrate and for water to drain. That affects yields, profitability, and ultimately, sustainability.

And this is where MAN’s 18.340, with its flotation tyres and AIR-CTI, is proving invaluable.

Built to Tread Lightly

According to David, the MAN has several advantages that make it the truck of choice for spreaders nationwide.

“For starters, it’s up to a tonne lighter than some competitor trucks,” he explains. “That matters when you’re running across soft paddocks.”

The truck is shod with massive Michelin 495/70 24XM47 flotation tyres, designed to spread the load and improve traction compared to conventional truck tyres. But the real trick comes when conditions turn wet.

“On a firm paddock, you can run normal pressures, no problem,” David says. “But when it’s wet and soft, you need more footprint. That’s where CTI shines. I can drop pressures to 30 PSI at the push of a button, and suddenly the tyre spreads out, floating on the soil instead of digging into it.”

The Science of Compaction

The benefits of this system aren’t just anecdotal. A joint study by UTAS and the Tasmanian Institute of Agricultural Research revealed that nearly 70 per cent of soil compaction comes from machinery traffic. The same research concluded that preventing compaction is far cheaper than repairing it.

International studies back this up. Trials in Ontario, Canada, showed that lowering tyre pressures for field work reduced fuel use by 14 per cent while improving traction. In Scotland, Michelin’s tests found a 36 per cent reduction in soil compaction and a nine per cent saving in fuel when CTI was used.

David nods. “There’s no doubt about it, the data’s there. And as operators, we see it every day. Lower pressures mean less rutting, better traction, and a smoother ride for us in the cab.”

Smoother for the Truck, Too

The benefits extend well beyond the paddock.

“When you lower tyre pressures in the field, you’re not just protecting the soil,” David explains. “You’re protecting the truck. There’s a lot less vibration and shock loading going through the chassis, springs, and spreader bin.”

That translates to longer component life, fewer maintenance headaches, and lower operating costs.

“The bearings and seals in the AIR-CTI are top-notch,” he adds. “We’ve never had a failure. As long as you service it, it’ll keep working for years.”

Productivity at the Push of a Button

The MAN’s AIR-CTI system is designed for ease of use, with three preset pressure modes and manual fine-tuning via simple buttons.

“I can run highway pressure on the road, then drop them to 30 PSI when I hit the paddock—all from the cab,” David says. “Front and rear axles can be adjusted separately, which helps balance traction.”

The result? More productivity and less downtime.

“These tyres aren’t cheap,” David says with a grin. “Looking after them is key. With AIR-CTI, I’m not only saving fuel, I’m extending tyre life. That’s money straight back in the pocket.”

Under the Cabin: MAN 18.340

The MAN TGM 18.340 is no ordinary farm truck.

Under the cab sits the D0836 6-cylinder inline engine, a 340hp twin-turbocharged, intercooled unit with common rail injection. It’s paired with MAN’s TipMatic automated transmission (ZF AS Tronic), specially tailored for vocational work.

Phil Salter from Westar Trucks, MAN’s Tasmanian dealer, explains:

“The off-road functionality is excellent. The TipMatic has a ‘Dx’ mode, which delivers faster shifts and a broader rev range for off-road use. SmartShifting adapts to conditions, keeping momentum on hills and reducing interruptions in traction.”

The truck also comes standard with an Engine Valve Brake (EVB), cruise control, and electronic transfer case/lock management, all features that make life easier for operators moving between sealed roads and muddy paddocks.

The Southern Spreaders Advantage

Of course, the truck is only half the equation. On the back sits a Southern Spreaders 750 Chain Contractor bin, purpose-built for contractors and large farms.

The chain-driven design is particularly suited to hilly Tasmanian terrain, delivering consistent spread patterns up, down, and across slopes.

“This unit is brilliant for heavy products,” David explains as a load of lime dust trickles steadily from the spreader. “The hydraulic conveyor doesn’t clog, and we can achieve wide spreads, which means fewer passes, less compaction, and more efficiency.”

Another standout feature is the GPS integration.

“If I slow down in rough going, the GPS automatically adjusts the flow rate so the spread stays consistent,” David says. “It also maps where we’ve been, giving farmers a digital record of placement. That’s proof of application, and it stops double spreading.”

Before GPS, contractors like David often waited hours at farm gates while clients decided where the product should go. Now, jobs are planned and mapped before the truck even leaves the yard.

“It saves us time, and it saves farmers money,” David adds.

Six and Counting

Reliability has been another selling point.

“They must be good—we’ve got six of them now,” David laughs. “And they just don’t miss a beat.”

For Earley Spreading, the combination of MAN’s robust platform, Southern Spreaders’ engineering, and CTI’s productivity benefits has created a winning formula.

“Yes, we’re saving money as operators,” David concludes. “But the real winners are the farmers. Healthier soil, better crops, less fuel burned, and proof-of-placement records. It’s the kind of technology that makes everyone’s business stronger.”

The Bigger Picture: Farming Smarter

Tasmanian agriculture is under pressure to deliver more with less – less land, less labour, fewer inputs. Technology like AIR-CTI and precision spreading systems represents a step toward smarter, more sustainable farming.

For operators like David and Bill Earley, adopting innovations isn’t optional—it’s essential.

“Margins are tight,” David says. “If you’re not looking for ways to improve, you’ll get left behind. The MAN helps us keep ahead.”

And as the rain returns, soaking into soils that are just a little less compacted thanks to a German truck and some clever engineering, it’s clear that “treading lightly” is more than a marketing slogan—it’s a farming revolution.

Air-CTI: How It Works

Central Tyre Inflation (CTI) is one of those technologies that looks simple on the surface but makes a world of difference in the paddock. At its heart, AIR-CTI gives the driver fingertip control of tyre pressures while the truck is moving.

The Basics

• Air supply: The system uses the truck’s onboard compressed air.
• Valves & seals: Air lines run through specially designed wheel-end seals that can inflate or deflate tyres while rotating.
• Control unit: Inside the cab, a controller allows the operator to select preset pressures or fine-tune PSI for road, paddock, or in-between conditions.

Why It Matters

• Bigger footprint: Lowering tyre pressure increases the contact patch, spreading the vehicle’s weight over a larger area. This reduces ground pressure and soil compaction.
• Traction gains: A wider footprint means less wheel slip, reducing rutting and erosion in soft soils.
• Fuel savings: Improved traction translates to less wasted energy — studies show up to 14% fuel savings in the field.
• Tyre life: Running at the correct pressure for conditions reduces heat build-up and uneven wear, extending tyre life.

On the Job

With AIR-CTI, drivers can hit the highway at 80 PSI, then drop to 30 PSI the moment they roll into the paddock. When the job’s done, it’s back to highway pressures at the touch of a button — no spanners, no waiting around.

As Earley Spreading’s David Cruthers puts it:

“I wouldn’t run a spreader truck without AIR-CTI. It saves us money, it saves the farmers money, and it keeps the soil healthy. That’s a win all round.”

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