Best Onboard Air System for Air Lockers 2026
Air lockers need a steady, high-volume air supply to engage instantly and stay engaged under load — a small pump built for topping up tyres once a week won't cut it. This guide ranks the onboard air system options worth running behind twin lockers on 4WDs used for touring, towing and off-road work in 2026.
- The Boss Auto PX06 pressure controller kit is the strongest all-in-one onboard air system for air lockers in 2026 — Buy.
- The PX07 3/4HP compressor suits twin-locker rigs needing faster recovery between engagements — Buy.
- A 5 gallon aluminium air tank adds reserve volume for vehicles running lockers plus tyre inflation off one system — Consider.
- Owners with an existing ARB compressor can add the ARB-compatible controller kit instead of replacing hardware — Consider.
Why this matters
Air lockers pull air fast, especially when a driver is working a diff locker repeatedly on a rutted track or a rocky climb. A compressor sized for tyre top-ups alone will lag, and a system with no reserve tank means the locker solenoid is drawing straight off the pump every time.
The PX06 pressure controller kit solves that by pairing the compressor with a 9 litre integrated tank, so the locker draws from stored air first and the compressor only cycles in to top the tank back up. That's the difference between a locker that engages on the first try and one that hesitates on a rocky ledge in 2026-spec vehicles running twin lockers front and rear.
Getting this wrong doesn't just mean slower engagement. Undersized systems run compressors near-continuously, which shortens compressor life and increases the chance of a water trap or fitting failure at the worst possible time — mid-track, with a locker half-engaged.
How this list was ranked
Each system on this list is assessed against four criteria that matter specifically for air locker use: air delivery rate relative to twin-locker demand, reserve tank volume, compatibility with existing compressor setups already fitted to Australian 4WDs, and durability of fittings and water traps under repeated cycling. Product specifications are drawn from Boss Air Suspension's own onboard air range as listed in 2026. Nothing here is drawn from lab testing claims — the ranking reflects component specification and application fit, not independent bench results.
The ranked list
1. Boss Auto PX06 Pressure Controller Kit — the complete package
This kit bundles the PX06 12V compressor with a 9 litre tank, fittings, water trap and Nitto coupling in one box. For a vehicle running dual air lockers from scratch, it's the fastest way to get a compressor, storage tank and plumbing sorted without sourcing components separately.
The 9 litre tank gives the lockers a reserve to draw from instead of relying on the compressor cycling live, which matters when a driver is working a locker repeatedly over a short stretch of track. Verdict: Buy — the standard choice for a ground-up onboard air build in 2026.
2. PX07 3/4HP Compressor — the workhorse for twin lockers
The PX07 3/4HP compressor is the higher-output option in the Boss range, sold bare for owners building a custom air management setup rather than buying a bundled kit. A 3/4HP unit recovers tank pressure faster than a smaller compressor, which matters most on vehicles running both front and rear lockers off the same air source.
It's the right pick when you're pairing a compressor to a larger tank you already own, or upgrading from a smaller pump that's struggling to keep up. Verdict: Buy for twin-locker rigs; overkill for a single rear locker only.
3. 5 Gallon Aluminium Air Tank — the reserve upgrade
A 5 gallon aluminium air tank sold bare gives you the largest storage option in the standard Boss lineup, with five ports for running locker lines, tyre inflation and an air horn or other accessory off one tank. More stored volume means fewer compressor cycles per locker engagement.
This is the one to add if your current tank is under 3 gallon and you're finding the compressor running more than you'd like during a day of low-range work. Verdict: Consider — pairs best with a compressor already sized for twin lockers rather than replacing the compressor itself.
4. Boss Auto Controller for ARB Compressors — the retrofit option
Some vehicles already have an ARB-branded compressor fitted from a prior air locker install. The ARB compressor fitting kit adds a Boss pressure controller, fittings and water trap designed to work alongside that existing compressor, rather than replacing hardware that's already doing the job.
This keeps the retrofit cost down and avoids pulling a working compressor off the vehicle. Verdict: Consider for owners with a serviceable ARB compressor already in place.
5. Boss Auto PX03 Compressor and Fitting Kit — the budget option
The PX03 kit is a smaller-footprint compressor and fitting bundle, suited to single-locker setups or vehicles where onboard air is a secondary function behind tyre inflation. It's not built for the continuous demand of twin lockers working hard on a technical track.
Verdict: Consider for single-locker vehicles only; Skip if you're running front and rear lockers together.
6. Impressor Digital In-Cab Controller — the control layer, not the air source
A digital in-cab controller adds pressure readout and switch control from the driver's seat, but it doesn't generate or store air on its own — it sits on top of a compressor and tank system already in place. Worth adding once the air source is sorted, not before.
Verdict: Consider as an add-on once the compressor and tank are chosen; Skip if you're still deciding on the air source itself.
Comparison table
| System | Best for | Tank included | Verdict |
|---|---|---|---|
| PX06 pressure controller kit | Ground-up twin-locker build | 9 litre | Buy |
| PX07 3/4HP compressor | High-demand twin lockers | Sold separately | Buy |
| 5 gallon aluminium air tank | Adding reserve volume | 5 gallon (bare) | Consider |
| ARB-compatible controller kit | Retrofit with existing ARB compressor | Fittings only | Consider |
| PX03 compressor and fitting kit | Single-locker, budget build | Compact | Consider |
| Digital in-cab controller | Control layer add-on | N/A | Consider |
Where to buy
- Buy the compressor and tank as a matched pair where possible — a bundled kit like the PX06 removes the guesswork on fitting compatibility.
- If you're retrofitting onto an existing compressor, confirm the water trap and fittings in any add-on kit are rated for that compressor before ordering.
- Check tank port count against how many accessories you're running — a 3-port tank runs out of connections fast once lockers, tyre inflation and a gauge are all plumbed in.
FAQ
What is the best onboard air system for air lockers in 2026?
The Boss Auto PX06 pressure controller kit is the strongest all-in-one option for 2026, pairing a 12V compressor with a 9 litre tank so lockers draw from stored air rather than a live-cycling compressor. It suits a ground-up twin-locker build best.
Do I need a bigger compressor for twin air lockers than for a single locker?
Yes — twin lockers draw air faster and more often than a single rear locker, so a higher-output unit like the PX07 3/4HP compressor recovers tank pressure quicker between engagements. A smaller compressor sized for tyre inflation alone will lag on twin-locker setups.
Can I add an air locker system to an existing ARB compressor?
Yes, a Boss Auto controller kit built for ARB compressors adds the pressure controller, fittings and water trap without replacing the compressor itself. This suits owners with a working ARB compressor already fitted from a prior locker install.
How big a tank do I need for onboard air with lockers?
A 9 litre tank, as fitted in the PX06 kit, is a solid baseline for twin-locker setups, and a 5 gallon tank adds reserve for vehicles also running tyre inflation off the same system. Larger tanks mean fewer compressor cycles per locker engagement.
Is a digital in-cab controller necessary for air lockers?
No, a digital in-cab controller adds pressure readout and switch control but doesn't generate or store air itself. It's worth adding once the compressor and tank are chosen, not as a first purchase.
What's the difference between a bare and complete air tank?
A bare tank ships without fittings, letting you choose your own plumbing layout, while a complete tank includes the fittings needed to install straight away. Complete tanks suit most owners unless you're running a custom multi-port layout.
Will an onboard air system for lockers also run tyre inflation?
Yes, most Boss onboard air setups with a multi-port tank can run lockers, tyre inflation and an accessory line off one compressor and tank. Port count on the tank determines how many accessories you can plumb in at once.
One last thing
The most common mistake on twin-locker builds isn't the compressor — it's an undersized tank that forces the compressor to cycle on every single locker engagement. A 9 litre tank paired with the right compressor, as in the PX06 kit, cuts that cycling down and extends the life of the whole system through 2026 and beyond.
