What PSI Pressure Washer Do You Really Need?

A Complete & Practical Guide For Real Aussie Homes, Farms, Worksites And Everyone In Between

If you’ve spent any time at all researching pressure washers online or in store, there’s always a number tagged alongside it and that’s how it’s marketed.

Everything is PSI this and PSI that, 2000PSI, 3000PSI, 4000PSI and so on…

It’ s kind of like when you look at a cars performance, it’s talked about in horsepower, it seems like bigger must be better right?

But that's not always the case

In truth, PSI is only one factor in what pressure washer you need, it’s easy to go out and buy based on a number, but that’s actually a very common mistake people make. I’ve seen first hand people spend a lot of money on a machine only to end up with:

• Slower cleaning than expected

• Damage to surfaces

• Machine that doesn’t actually suit their application

We’re going to run through this guide together, and by the end you’ll have a better understanding of what PSI means and what other factors determine how you decide what machine you need, whether you’re in the suburbs cleaning around the house, have a large property with machinery, a workshop with grease and grime or anything else in between it all!

What Actually Is PSI?

PSI, pounds per square inch, tells us the force of the water exiting the machine. Think of it simply as how hard the water hits the surface.

Higher PSI = more force hitting dirt, grime, paint or anything else on the surface.

Now PSI is absolutely important for cleaning, but there’s more factors that assist the PSI to enable it to work efficiently. We need to also understand how much water is actually moving because in real world applications that matters just as much as the PSI. 

The Assisting Factor: Flow Rate (L/Min)

Now like we said, pressure is important for sure, but flow rate is what is going to push the machine to clean efficiently. 

In a perfect spot clean, direct to the task, pressure will break up dirt or some grime, but in a real world job, volume of water will remove it.

We often look at cleaning efficiency like this:

• PSI = Impact

• L/min = Speed

• Together = True Performance

If you have a machine with a lower PSI but a much higher flow rate, it will often: 

• Clean faster

• Rinse better

• Be more effective on larger areas

It’s this formulae that make high end commercial machines feel completely different to smaller electric units, not just pressure but the rate of which water is delivered.

Check out a couple of our products below, and you can see the difference in PSI and Flow rate

Maine 1409 & HyperC 1211 electric pressure washers

Why PSI Has The Headline

Truth is, it catches the eye to most people looking, and you can’t blame them, a 2300 PSI machine sounds more appealing than a 1800 PSI machine right?

It’s easier to understand, sounds impressive and helps most stores sell units.

But it doesn’t tell you:

• How quickly you’ll clean your driveway

• Whether it can handle mud vs grease

• How it performs over large areas and for long durations

And that’s where a lot of frustration comes in for people, because they buy based off PSI alone and the real world applications don’t actually meet the expectations.

Now Let’s Match PSI & Flow Rate To Real Life

Light Cleaning: Generally ← 1800 PSI and ~5-8L/min

This is where cleaning is delicate, and a low PSI & flow rate is perfect, we don’t want to be stripping any paint or damaging fragile surfaces. Think washing cars, bikes, outdoor furniture etc.

You’ll feel it blast but it’s controlled, gentle and safe. You’re not really ‘blasting’ anything off you’re just loosening dirt or light debris and rinsing it away, too much pressure here and it’ll damage.

General Home Cleaning: 1800 - 3000 PSI & ~7-10L/min Flow Rate

The perfect numbers for cleaning around the house, driveways, pathways, decks and anywhere that dirt or mud can build up and stain. 

This is also where flow rate is important here, have it too low and it’ll take longer to cover these larger areas. 

Large Property, Farm Use: ~3000 - 3500 PSI & ~10-15L/min Flow Rate

This is where cleaning starts to get aggressive, and where a flow rate/psi combo is important. A build up of bulk material and cleaning down equipment needs to be efficient.

Take mud build up for example. The higher PSI will help cut through the mud build up, but mud isn’t just stuck, it’s a lot of volume so having a low flow rate here will be slow clearing and take much longer.

Daily Trade / Commercial Use: 3000 - 4000 PSI & ~11 - 16L/min Flow Rate

High impact and max efficiency, this is where time is money and these machines are optimising time per job.

Cleaning down machinery as well as daily site cleans, made for long periods of use with no sight of slowing down.

Heavy Duty / Industrial: 3000 - 5000 PSI & ~12 - 21L/min Flow Rate

Machines of this size are normally paired with a hot water system as it’s handy for removing grease and stubborn build ups. The most efficient machines on the market.

The high PSI will break down stubborn materials and the high flow rate comes in behind to ensure no mess is left behind.

We’re more than happy to discuss this further, just give us our friendly team a call at 1300 079 161 or email at sales@aussiecultivators.com.au. 

Shop our range today and have a fantastic day.