Review of a commercial grade 5.5HP pressure washer: AMY HW4 P2300
I’m getting flooded with direct messages from folks asking about my pressure washer setup, so I thought it’ll be easier to post a short review of my main machines here. If you still have questions, kindly address them here and I’ll be happy to answer. This is currently my main washer although I still use the smaller one as well occasionally.
Technical Specifications:
Motor: 5.5HP/4000W
RPM: 1450
Hose: 15m R2 dual braided with swivel (upgraded)
Flow Rate: 15.8L/min - 4.18 GPM without nozzle
15.1L/min - 4 GPM with green 25 degree nozzle
Power cord: 3m
Pressure: 160 bar/2300 psi
Stock Nozzle size: 045
Warranty: 1 year on motor + pump
Oil change interval: First 50 hours of operation, thereafter every 100 hours
Oil type: 15W-40 full synthetic
Oil quantity: 750ml
Motor grease: ZL-3 Lithium grease
Gas vs Electric:
The eternal question when discussing heavy pressure washers, given indoor operation and the lower noise levels + less maintenance and no fuel needed for electric made it an almost no brainer that electric was the way to go. For remote applications however, gas washers remain unchallenged.
Why not a Karcher/Kranzle/AR commercial unit?
Two reasons: cost and availability of spares, I’ll explain.
Cost- for something like a Kranzle 1200 TS commercial I’m looking at at least 2.8-3L which I didn’t want to spend unless necessary. I’m getting the same (better in fact) performance with a high quality Chinese machine at 1/3rd the cost.
Spares and Service: commercial units are very modular and as such can run for years and years provided you service it on time and simply replace any part that fails, be it a motor/pump/switch/ etc.
I won’t speak for other countries but having experienced the brilliant Karcher service in India (sarcasm), I was in no mood to sign up for more pain anytime my machine needs service or spares. Neither do I want to wait weeks for parts. The machines themselves are top tier but the other aspects make it difficult to justify.
As for Kranzle, again great machines but zero support in India. No dealers in North India, one dealer in Mumbai and one further down south with both having dysfunctional websites and expired domains
As for Chinese machines, I’m not claiming every unit will be a good buy, but I trust my supplier from whom I’ve bought other machines and air compressors before and my smaller 3HP pressure washer over 2 years ago which still runs flawlessly in a commercial environment. All I’ve done with the smaller washer is an oil change every 75 hours of operation.
I also have a commercial Comet KL1600 and Karcher K4 compact (at home) but given the Comet’s low flow rate it’s only for emergency use.
Why upgrade if I already had other washers?
Two words: Flow rate! With pressure washers how quickly and effectively you clean all comes down to pressure and flow rate. In simple terms, pressure is how hard water hits a surface and flow rate is how much volume of water hits per minute.
For cars, we have a hard limit at roughly 2400 psi/165 bar where anything above has the potential for paint damage (below this can also damage if you bring the nozzle too close but that’s user error).
What sets a smaller unit that is pushing 150 bar from a larger, more powerful unit putting out the same pressure is the flow rate, measured in litres per minute (LPM) or gallons per minute (GPM).
The higher the flow rate, the faster and better the job performance. Bonus: you get thicker foam in your foam cannon with high flow rates, generally anything over 8L/min will give thick foam with shaving cream thick foam above 10L/min (Assuming good shampoo + a high quality foam cannon and soft water is used.)
To illustrate- on a regularly washed car, it takes 5-6 mins to complete a pre rinse with this unit compared to 10-12 mins with my smaller machine. With even smaller domestic machines it used to take me 15-20 mins washing at home.
Pneumatic tyres filled with 30psi ensure smooth movement
Pump close up
Under the hood
The machine can be run in continuous mode where the motor remains on or in total stop auto mode where it cuts in and cuts out depending on the trigger use, there is a 15 second delay once you let go of the trigger before it cuts out.
120 micron input filter and quick connectors for input pipe + hose. Input pipe is a braided 0.75” running to my tanks.
I upgraded the gun to a higher quality one with a swivel and the hose as well to a 15m R2 steel dual braided one from HoseX, stock was only 10m in length and R1 single braided.
Oil level indicator, the pump is big. Takes up 750ml of oil compared to 375ml on my smaller machine.
AMY (left), my smaller 3HP washer (right), observe the massive difference in pump size.
Conclusion:
It’s a brilliant machine with massive power, makes short work of any job - no matter how dirty a car is. Smooth operation and has been without issue till date, all I’ve done over the months are simple oil changes with synthetic 15W-40 every 75 hours (mfg says 100 hours) but I prefer 75 hours as the oil gets visibly darker in colour. Oil is cheap and pumps are expensive (I follow the same logic with my cars.)
It comes with an O ring kit in case pump seals need changing in the future but I’ve not had need for them yet. My other machine which is 2 years old is still on the original seals so I believe it’s not something that’s needed often. I use a vibration activated hour meter to track operating hours, very handy little device.
Once you use a washer with a high flow rate, trust when I say you’ll never go back to smaller machines, it’s like driving a very powerful car