A note on substitution first: this comparison was planned as Karcher against Ryobi, and no Karcher unit resolved in Amazon’s catalog when the picks for this site were built. Rather than write a comparison from spec sheets we did not have in front of us, it is Greenworks against Ryobi — two machines that genuinely do compete, both of which we could verify.
Where they differ
| | Greenworks 1600 | Ryobi 1800 |
|---|
| Catalog pressure | 1,600 PSI | 1,800 PSI |
| Catalog flow | 1.2 GPM | 1.2 GPM |
| Type | Corded electric, upright | Corded electric, cold water |
| Cleaning units (PSI x GPM) | 1,920 | 2,160 |
Identical flow, 200 PSI apart. That is a genuinely small difference — about 12 percent in cleaning units — and it will not be the thing you notice. What you will notice is handling, storage and how the hose and cord behave.
What both of these are for
Cars, bikes, grills, outdoor furniture, bins, a small patio, garden tools. At 1,600 to 1,800 PSI with a wide tip these are about as forgiving as a pressure washer gets: you would have to try quite hard to damage siding or paint with one. For a first machine in a household with no big concrete, that forgiveness is the feature.
Both are also small and light enough to carry up steps one-handed and store on a shelf rather than taking garage floor space, which is a bigger day-to-day factor than 200 PSI.
What neither of them will do
At 1.2 GPM you are limited to an 11-inch surface cleaner, and a large driveway will be a long afternoon with either. Neither will shift set-in oil — that is a chemical job at any pressure. And neither has meaningful onboard detergent capacity, so if soap matters you will want a downstream injector.
Which I would buy
The Ryobi if you already own Ryobi tools or value easy access to spares — hoses, tips and guns for these are easy to find, and 200 PSI of headroom is free. The Greenworks if the lowest possible risk to paint and siding is the point, or if the Greenworks is meaningfully cheaper on the day, which it often is.
If, having read this, you suspect you actually want more machine: you probably do, and the beginners roundup has the 1.76 GPM options that change what is possible.
