How much PSI and GPM do I actually need for home use?

Across r/pressurewashing and r/Tools discussions, the consensus for typical residential cleaning (cars, siding, fences, modest driveways) is roughly 2,500–3,400 PSI paired with at least 2.3–2.6 GPM. Reviewers repeatedly stress that GPM matters more than PSI for cleaning speed, especially if you want to run a surface cleaner — most threads recommend 4.0 GPM only if you're running a 15–20 inch surface cleaner regularly or doing it for pay.