Which BigBoi WASHR Should You Buy? DUO vs TRADIE vs PRO MKII
Alpha Details · Buyer's Guide
Which BigBoi WASHR should you buy?
DUO vs TRADIE vs PRO MKII. Three machines, three jobs — and the number most people shop on is close to the least useful one on the box.
We stock the range, we run them in our own studio in Melbourne, and we wash cars with them every week. This is the guide we wish existed when we were choosing.
The 30-second answer
The entry point to the range, and where most home garages should start. Bolt it to the wall and forget it: a semi-commercial German wobble-plate pump with a brass head, built for a fixed setup you use regularly.
The lightest of the three at 19 kg, with a commercial triplex pump. Built to be thrown in and out of a vehicle.
Most working pressure, most flow, an Italian forged-brass triplex pump, and a quiet 80 dB. The PRO MKII kit and the TRADIE kit are both $999. Unless you need to carry it, that decision makes itself.
Looking for the WASHR QUAD?
The QUAD has been discontinued and we no longer stock it. If you came here looking for it, the closest machine in the current range is the WASHR DUO kit at $899 — more pressure and more flow than the QUAD delivered, though it is built to be wall-mounted rather than carried.
The full comparison
Every figure below is taken from BigBoi's published product specifications and cross-checked against their manufacturer listings. Only two of the three machines are tuned down from a higher peak — we've shown working and peak figures separately so nothing is overstated.
| WASHR DUOFixed / commercial | WASHR TRADIEMobile pro | WASHR PRO MKIIHigh-end commercial | |
|---|---|---|---|
| Working pressure what you actually get | 1,350 psi | 1,300 psi | 1,450 psi |
| Peak pressure | 1,400 psi | 1,300 psi | 1,850 psi |
| Working flow at the nozzle | 7.7 L/min | 8.8 L/min | 9.2 L/min |
| Peak flow | 8.5 L/min | 8.8 L/min | 9.5 L/min |
| Motor | 1,500 W induction | 1,800 W induction | 2,000 W brushless induction |
| Pump | German wobble-plate, brass head | Commercial triplex head | Italian triplex, forged brass |
| Noise | not published | not published | 80 dB |
| Weight (carton) | 22 kg | 19 kg | 31 kg unit / 28 kg kit |
| Max water temp | 60 °C | 60 °C | 60 °C |
| Power | 220–240 V · 50 Hz · 10 A — all three run off a normal household outlet | ||
| Wall mountable | Yes — all three | ||
| Foam cannon included | Yes — 3-way large-mouth foam cannon, in every box | ||
| Price — unit only | $699 | $799 | $899 |
| Price — complete kit | $899 | $999 | $999 |
How we've read BigBoi's numbers
Only the DUO and PRO MKII are tuned down from a higher peak. The PRO MKII can hit 1,850 psi but arrives set to 1,450; the DUO peaks at 1,400 but runs at 1,350. The TRADIE publishes a single working figure (1,300 psi / 8.8 L/min), so its working and peak numbers are the same — it isn't detuned.
Noise. BigBoi rates the PRO MKII at 80 dB. It does not publish a figure for the DUO or the TRADIE, so we haven't quoted one rather than guess.
A spec-sheet typo to ignore. BigBoi's sheet prints the PRO MKII's flow as 9.5 L/s. That would be 570 litres a minute — roughly a fire hose. Their own body copy says 9.5 L/min, consistent with the rest of the range. It is a typo, not a spec — we mention it only because if you are comparing on paper you will hit it.
Why PSI is the wrong number to shop on
Here is the thing that surprises people: on the two machines that offer it, BigBoi deliberately tunes the pump down from its peak pressure. The PRO MKII can hit 1,850 psi but arrives set to 1,450; the DUO peaks at 1,400 but runs at 1,350. (The TRADIE isn't detuned — it publishes one working figure.)
That is not a limitation. That is the design philosophy, and it is correct.
A pressure washer cleans by delivering energy to a surface. You can deliver that energy two ways: concentrate a small volume of water very hard, or move a large volume of water at moderate force. On a driveway, the first works fine. On paint, the first is how you drive grit into a clearcoat instead of carrying it off.
What you actually want on a car is volume — enough water, moving fast enough, to lift and float contamination away from the panel and off the car. That is flow, measured in litres per minute. It is why a 9.2 L/min machine will out-clean a 7.7 L/min machine on a filthy car — the extra volume carries more grit away — even when the pressure numbers aren't far apart.
Flow is also what makes foam. A foam cannon works by drawing solution through a venturi and mixing it with air and water. Starve it of flow and you get thin, watery foam that runs off the panel in twenty seconds. Feed it properly and you get the thick, clinging foam that actually gives your pre-wash chemistry the dwell time it needs to work.
Pressure gets dirt moving. Flow gets it off the car. For detailing, flow wins — and it is the number most brands bury.
What none of these machines will do
No pressure washer removes bonded contamination. Iron fallout, tar, tree sap and industrial fallout are chemically stuck to your paint, and no amount of psi will shift them without also risking the clearcoat. That is a job for chemical decontamination and clay, not water. A pressure washer's job is the safe removal of loose contamination before anything touches the paint — and that is precisely the job all three of these are tuned for.
Pumps: the part that decides how long it lasts
The pump is the most expensive component in a pressure washer and the one that determines its duty cycle — how long it can run, how often, before it complains.
Wobble-plate — WASHR DUO
A swash plate driven by the motor pushes pistons back and forth. Simple, compact, cheap to build and perfectly capable — but it runs the pistons at an angle, so there is more side-loading and more heat. It is a semi-commercial design: excellent for a fixed setup washing cars regularly, less happy running flat out all day. The DUO's brass head is a meaningful upgrade over the plastic heads you will find at this price point elsewhere.
Triplex — WASHR TRADIE and WASHR PRO MKII
Three pistons driven straight off a crankshaft, in line with the direction of travel. Less side-loading, less heat, longer service life and — crucially — serviceable. This is the pump architecture you find in genuine commercial equipment. The PRO MKII's is an Italian-designed forged-brass commercial-duty unit; the TRADIE runs a commercial triplex head in a lighter, more portable body.
Noise: quieter than you'd expect — and not the number to choose on
Good news that simplifies the decision: these are quiet machines. BigBoi rates the PRO MKII at 80 dB — far quieter than the universal-motor pressure washers you'll find in a hardware store, and civil enough for a garage attached to a house. BigBoi doesn't publish a figure for the DUO or the TRADIE, so we won't put a number on them.
The reason they run quiet is the motor architecture: induction and brushless motors run cooler and smoother than the cheap universal motors used in hardware-store machines. In practice, noise is not the spec to choose between these three on. They are all quiet for what they are. Choose on flow and on where the machine will live.
The two decisions people get wrong
1. TRADIE vs DUO
Close on paper, and the numbers cut both ways. The DUO has more pressure (1,400 psi peak, 1,350 working, against the TRADIE's 1,300). The TRADIE has more flow (8.8 L/min against 8.5) and a commercial triplex pump. Neither is decisively “more powerful,” and that is not the decision.
The real decision is where the machine lives. The TRADIE is 19 kg with a commercial triplex pump — built to be lifted in and out of a van. The DUO is 22 kg with a wobble-plate pump — built to be bolted to a wall and left there. Buy for the job, not the spec sheet.
2. Buying the unit when you should buy the kit
The PRO MKII is $899 as a bare unit and $999 as a complete kit — hose, professional short trigger gun, quick-release nozzles and fittings. A hundred dollars for everything you need to actually use it.
And note where that lands: the PRO MKII kit is $999. The TRADIE kit is also $999. Same money. If you are not carrying the machine anywhere, the PRO MKII gives you more working pressure, more flow and a better pump — for the identical price.
The WASHR PRO MKII kit at $999
It is the most capable machine BigBoi makes — the most working flow and pressure, an Italian forged-brass triplex pump — and at kit price it costs the same as the TRADIE. The only reason not to buy it is if you need to carry your pressure washer to the car, instead of the car to your pressure washer.
View the PRO MKII kit →What you will want alongside it
A foam cannon that actually foams. Every WASHR ships with a 3-way foam cannon in the box — but if you are running two chemicals, or want one permanently set up, the FOAMR PRO+ twin-bottle system is the upgrade.
Snow foam worth putting through it. A great machine and a bad pre-wash chemical is a waste of a great machine. See our wash and pre-wash range.
The rest of the BigBoi ecosystem. BLOWR touchless dryers, SUCKR vacuums and D-IONIZR spot-free rinse systems — all designed to work together.
Questions we get asked
Which BigBoi WASHR is best for a home garage?
The WASHR DUO — $699 as a unit, $899 as a complete kit. It is the entry point to the current range, and its German-designed wobble-plate pump with a brass head delivers 1,350 psi working and 7.7 L/min, comfortably enough for safe, effective car washing. It is built to be wall-mounted and left in place, which suits most home garages. If you need to carry the machine to the car rather than the car to the machine, look at the 19 kg TRADIE instead.
Is more PSI better for washing a car?
No. Beyond a point, more pressure increases the risk of driving grit into your clearcoat rather than carrying it away — which is why BigBoi tunes the DUO and PRO MKII down from their peak pressure. For car detailing, flow rate (litres per minute) matters more than pressure: volume of water is what lifts and floats contamination off the panel, and flow is also what generates thick, clinging foam through a foam cannon. Pressure gets dirt moving; flow gets it off the car.
What is the difference between the WASHR TRADIE and the WASHR DUO?
They are close. The TRADIE ($799) has more flow (8.8 L/min against 8.5) and a commercial triplex pump head; the DUO ($699) has more pressure (1,400 psi peak, 1,350 working, against 1,300) and a German-designed wobble-plate pump with a brass head. The real difference is portability: the TRADIE is 19 kg and built for mobile detailers working out of a van; the DUO is 22 kg and built for a fixed, wall-mounted setup.
Is the WASHR PRO MKII worth the extra money over the TRADIE?
As complete kits they cost the same — both are $999. At that price the PRO MKII gives you more flow (9.2 L/min working against 8.8), more working pressure (1,450 psi against 1,300) and an Italian-designed forged-brass commercial triplex pump. The only reason to choose the TRADIE is portability: it is 19 kg against the PRO MKII's 31 kg.
How loud are the BigBoi WASHR pressure washers?
Quiet, for pressure washers. BigBoi rates the PRO MKII at 80 dB — far quieter than a typical hardware-store unit, thanks to its brushless induction motor. BigBoi doesn't publish a figure for the DUO or TRADIE. In practice all three are civil enough for a suburban garage, so noise is not the spec to choose on.
Do you still sell the BigBoi WASHR QUAD?
No — the WASHR QUAD has been discontinued and we no longer stock it. The closest machine in the current range is the WASHR DUO, which delivers more pressure (1,350 psi working against the QUAD's 1,050) and more flow (7.7 L/min against 7.45), though it is designed to be wall-mounted rather than carried.
Will a BigBoi WASHR remove tar, iron fallout or tree sap?
No — and neither will any other pressure washer. Those are bonded contaminants, chemically stuck to your paint, and no amount of pressure will remove them without risking the clearcoat. They require chemical decontamination (a dedicated iron remover and tar solvent) followed by clay. A pressure washer's job is the safe removal of loose contamination before anything touches the paint.
Do BigBoi WASHR pressure washers need special power?
No. All three models run on standard Australian domestic power — 220–240 V, 50 Hz, 10 A. You do not need a dedicated circuit or a 15 A outlet.
All specifications above are taken from BigBoi's published product data and cross-checked against their manufacturer listings; verified 15 July 2026. Prices are current at time of writing and are in AUD. Only the DUO and PRO MKII are tuned below their peak pressure; the TRADIE publishes a single working figure. The WASHR QUAD, covered in earlier versions of this guide, has been discontinued and is no longer stocked. Where a number is decisive for your purchase, check the relevant user manual, or call us on 0400 976 972 and we will talk it through.