No one can give you a definitive answer about whether petrol, diesel, or electric is better. The question comes down to you: what do you need your pressure washer to do?
For example, an electric washer is great if you have easy access to a house socket where you can plug in it. Using an extension cable should always be avoided when possible. So if you won’t be leaving your patio or driveway, an electric machine can give you all the power you need cheaply.
But if you are looking for mobility, a machine driven by an engine is what you’ll need. So now you’re looking at either diesel or petrol.
Petrol is much cheaper to buy upfront, but running the machine may have more costs associated with it. Diesel will be cheaper to run in the long term.
Beyond mobility, there are some other advantages to electric washers you should keep in mind. With an electric pressure washer, you can avoid fumes. That means they are safe to operate indoors. They are also quieter. And without the engine, you may avoid needing as many repairs.
And of course, you can’t forget about the convenience and price that comes with not needing fuel!
So really, it comes down to where you’ll be operating your machine, what you’re willing to pay for it, and how much you can spend on running it. There may also be more power to some, so you will want to examine the machine’s available pressure closely.