Which power
The honest rule: buy petrol for the absent socket, not for the pressure.
Two questions decide this, and pressure is not one of them.
If yes, an electric machine is cheaper, quieter, starts instantly and needs no maintenance. The Kärcher K 7 WCM at 180 bar and 600 l/h cleans anything a house has.
If no — a paddock, a boatyard, a second property, a farm gate at the end of a track — petrol is the only answer, and that is the whole argument.
Petrol machines tolerate hours of continuous work. Domestic electric machines are designed for intermittent use, which is why the water-cooled motor on the top Kärcher exists.
Fumes — never indoors or in a garage, the exhaust is carbon monoxide. Maintenance. Noise. And a pressure level that will damage most of what a house is made of: at 221 to 234 bar, technique stops being a preference.
The BTGSHYNM at about 152 bar is the pressure of a good electric machine with no cable — which, for a large garden without power, is exactly the right specification.
180 bar · 600 l/h · 60 m²/h · water-cooled motor
The top of the domestic range, and the only one here whose motor is water-cooled — which is a statement about running time, not power.
Best for: Large areas cleaned in one session — long drives, farmyards, several vehicles — where the machine runs continuously rather than in bursts
≈ £590 / 500 €
Rarely. At that level you are cleaning concrete yards, farm machinery and stonework. The same pressure removes the surface of softwood decking, drives water behind render and strips paint. Domestic machines top out around 180 bar for a reason.
Oil changes on schedule, an air filter, a spark plug, and either fuel stabiliser or an empty tank over winter. That is genuinely more work than an electric machine — and it is why a petrol washer left in a shed for a year usually will not start when you want it.
Pressure washers and floor washers swing by a hundred euros or more across the year, and the biggest "discounts" often land at prices the same model sold for six weeks earlier. UniverTrack tracks the real price history across retailers, spots fake reductions, and alerts you when it is genuinely the moment to buy.
