What PSI Pressure Washer Do You Need? (Car, Deck, Concrete)
Match pressure washer PSI and GPM to the job, from washing a car to blasting a stained driveway, plus which nozzle to use and why too much pressure can do damage.
More pressure isn’t always better. Too much can strip paint off a car, gouge a wood deck and force water behind siding. Too little and you’ll be out there all day on a stained driveway.
The quick chart
| Job | Suggested PSI | Nozzle |
|---|---|---|
| Cars and boats | About 1,200 to 1,900 | 40 degree (white) or soap |
| Patio furniture, grills | About 1,300 to 2,000 | 25 or 40 degree |
| Vinyl siding | About 1,300 to 2,000 | 25 or 40 degree |
| Wood decks and fences | About 1,500 to 2,500, start low | 25 or 40 degree |
| Composite decking | Follow the decking maker’s limit | 40 degree |
| Concrete driveways and sidewalks | About 2,500 to 3,000+ | 15 or 25 degree, or surface cleaner |
| Brick and pavers | About 2,000 to 3,000 | 25 degree |
These are common starting points. Always start with the widest nozzle and lowest pressure, test in a hidden spot and work up. Your siding, decking or car manufacturer's care instructions come first.
PSI vs GPM
- PSI (pounds per square inch) is the force that loosens dirt.
- GPM (gallons per minute) is the water flow that rinses it away.
A washer with higher GPM cleans faster at the same PSI. To compare overall power, multiply them: cleaning units = PSI x GPM. A 3,000 PSI, 2.0 GPM washer (6,000 cleaning units) does big jobs much faster than a 2,000 PSI, 1.2 GPM washer (2,400).
In Bob Vila’s 2026 testing, the 3,000 PSI, 2.0 GPM Greenworks GPW3001 cleaned a concrete driveway nearly twice as fast as the next-best electric washer.
Which pressure washer size do you need?
- Light duty, up to about 1,900 PSI: cars, patio furniture, grills, small decks. Most compact electrics.
- Medium duty, about 2,000 to 2,800 PSI: siding, decks, fences, small driveways. Most full-size electrics.
- Heavy duty, 3,000 PSI and up: big driveways, stained concrete, paint prep. The strongest electrics, battery models like the 3,200 PSI Ego, and gas.
Nozzles explained
| Color | Angle | Use |
|---|---|---|
| Red | 0 degree | Spot-blasting tough stains on concrete only. Can cut skin and wood. |
| Yellow | 15 degree | Concrete, stripping |
| Green | 25 degree | General cleaning, decks, siding |
| White | 40 degree | Cars, windows, delicate surfaces |
| Black | Soap | Low pressure, applies detergent |
Avoid damage
- Hold the wand 1 to 2 feet away and move closer only if needed.
- Keep it moving and work with the grain on wood.
- Spray siding downward at an angle so water doesn’t get behind it.
- Never point the wand at people, pets or windows up close.
- Use a surface cleaner attachment for big concrete areas. It’s faster and avoids stripes.
Short answers
What PSI do I need to wash a car? About 1,200 to 1,900 PSI with a 40-degree nozzle or foam cannon is plenty.
What PSI for a concrete driveway? About 2,500 to 3,000 PSI or more, ideally with a surface cleaner.
Is 2,000 PSI enough for a deck? Usually, yes. Start lower on soft woods like cedar.
See our picks for the best electric pressure washers for home use.