In short, it’s best used for medium-sized cleaning tasks such as cleaning your car, wheelie bin, garden furniture, patio and more. For comparison, the 2,100W model (19.2kg) – which B&Q says is suited to cleaning larger patios, paths and garden stone walls – offers a maximum pressure of 140 bar and a 450l/h flow rate. Meanwhile, the low-end 1,300W model (9.6kg) gives you a 100-bar maximum pressure and a 390l/h flow rate. All three machines work with water up to a maximum temperature of 50 °C. Fewer owners of Karcher pressure washers experienced faults within the first seven years of owning it - 8% said they had (sample size: 2,271) versus 16% of Nilfisk owners (sample size: 185). If you just need a pressure washer for light cleaning, then most no-frills machines come with just one lance, which is a long tube with a nozzle on the end. The nozzle will usually provide variable pressure – when you twist the nozzle, you can adjust the spray from a powerful narrow jet to a more broad gentle fan.

Basic machines come with one lance – a long tube with a nozzle at the end. A fixed lance can’t be adjusted, though you can move it nearer or further away from the area you’re trying to clean. You can also buy models with a variable pressure lance, where you can twist the nozzle at the end to alter the power of the spray – rather like a hosepipe attachment. This lets you create either a powerful narrow jet of water or a gentler, broad spray. The window and patio cleaning tests factored in whether the pressure washer left an attractive streak-free appearance, and during muddy car washing, they paid particular attention to whether the pressure washer was able to access all the nooks and crannies, including wheel arches and the underside of the car. If you’ve ever tried to take on a muddy patio with just a brush and some elbow grease, you’ll know that some garden jobs just need a little extra investment. To choose the best pressure washer for you it is worth taking time to think about what you'll be cleaning, how dirty it will be and how often you'll use it. Medium duty pressure washers tend to be a mix of high-end own-brand models and cheaper premium-brand models. As such, you'll find a confusing array of high-powered-but-basic models by garden machinery brands such as Stihl or Nilfisk, mid-powered Karcher, Bosch or Vax models with some choice of accessories, and high-powered and highly accessorised machines from Qualcast and Mac Allister.

Pressure gauge: some more expensive models have a pressure gauge on the lance handle but, as the pump pressure doesn't vary, they're of little practical use.

To be fair, that problem isn’t exclusive to this particular pressure washer, but at least with the Mac Allister 2,100W you get a built-in cable winder to help keep things tidy. Detergent tank: we found built-in but removable detergent tanks more convenient than bottle attachments in our tests. Having recently cleaned my patio while testing the Kärcher K4 Full Control, I decided to put the Mac Allister through its paces by cleaning my car, my wheelie bin and my conservatory roof.

The Mac Allister 1,800W is a cheap and powerful pressure washer with only a few flaws

This all depends on how much you can afford and how powerful and durable you want your pressure washer to be. Best for: Cleaning small areas of lightly soiled paving, bicycles, small cars and garden furniture. That’s where power washers come in. These efficient machines make light work of a deep clean, whether you’re sprucing up your patio and grill for BBQ season, giving your bike a much-needed wash after your latest cycling adventure, or giving your car a shiny new facelift. Nilfisk pressure washers tend to be quieter than Karcher models as they're designed with a noise-reduction system. Toolstation has electric and petrol pressure washers, some of which are bundled with a patio cleaner.

The first thing you need to consider when investing in a pressure washer is which area or outdoor items you’re looking to clean. This will determine how much pressure – measured in bars – you need your washer to have.

Karcher has a higher customer score of 78% (sample size: 2,271) versus Nilfisk's 74% (sample size: 185). This reflects how satisfied respondents are with the brand and how likely they would be to recommend it. Nilfisk models are typically more lightweight compared to Karcher models. They are constructed with light materials to make them easier to move around. Best for: Cleaning extensive areas of paving, grimy 4-wheel drive vehicles, commercial vehicles and caravans