Every pressure washer gets a score from 0 to 100% built from four factors, which maps onto the 5-point rating shown on the site (a 0% score would be 1.5 stars; a perfect score, 5). Each factor is scored against fixed reference points, not against the other products in the list, so adding a new model never moves another model’s rating. Washers are grouped by power source, electric and gas, and each group has its own scales.
| Factor | Measures | Weight |
|---|---|---|
| Value | price per 1,000 cleaning units | 35% |
| Cleaning power | PSI x GPM | 30% |
| Hose | high-pressure hose length | 10% |
| Warranty | warranty length | 25% |
Where the numbers come from
Pressure, flow, engine or motor, pump, hose, weight, warranty and the rest come from the maker’s product page, spec sheet or manual, or the maker’s own copy on its Amazon listing. When a maker gives both a rated working pressure and a higher peak, the rated figure is used. Prices are checked at Amazon and the maker’s own store, and the lowest is used.
The factors
Value is the current price divided by the cleaning units (PSI x GPM), per 1,000 cleaning units, on a log scale for each group, so going from $60 to $30 counts as much as going from $120 to $60.
| Group | Scores 0 | Full marks |
|---|---|---|
| Electric | $160 per 1,000 | $45 per 1,000 |
| Gas | $90 per 1,000 | $35 per 1,000 |
Cleaning power is the cleaning units: for electric washers 1,800 scores zero and 3,300 full marks; for gas washers 5,000 scores zero and 11,000 full marks.
Hose is the length of the high-pressure hose: 20 ft scores zero and 35 ft full marks. A longer hose means moving the washer less often.
Warranty is the length of the consumer warranty on the washer: 1 year scores zero and 5 years full marks. A longer warranty on the pump or frame alone is noted on the product page but not scored.
What isn’t scored
Pump type, nozzles, detergent tanks, cord length and weight are listed but not scored. A triplex pump is the biggest of these for long life, and the “Triplex pump” filter shows only those. Independent tests are listed where they exist, but there are too few to score.
Missing data
If a figure isn’t published, that factor gets the neutral middle score (50) and the product page marks it as estimated.
Ties and discontinued models
Products are ranked by score within each group. Discontinued models stay listed but rank below every current model and can be hidden with the “Hide discontinued” filter.