How much PSI do I actually need in an electric pressure washer?

For cars and outdoor furniture, 1,500–2,000 PSI is plenty and safer for paint. For decks, fences and siding, 2,000–2,500 PSI is the sweet spot most reviewers recommend. For driveways and heavy concrete grime, look for 2,500–3,000 PSI paired with at least 1.2 GPM rated flow — specialist subreddits repeatedly point out that GPM matters as much as PSI for cleaning speed.