Westinghouse WPX3800
#3 in GasFull review
For big properties and frequent users who want near contractor flow for less than a Honda powered Simpson.
Amazon $737.63$737.63
The Westinghouse WPX3800 is the better pressure washer overall, rated 4.0 to 3.4. The Westinghouse WPX3800 leads on value. The Westinghouse WPX3800 costs $659.37 less ($737.63 vs $1,397).
Simpson Aluminum 4200 PSI
#9 in GasFull review
For pressure washing businesses that want a CAT pump and a rustproof frame at full 4 GPM flow. The steel frame PS4240 does the same work for less.
Amazon $1,397$1,397
Prices were last checked October 31, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the Westinghouse WPX3800 for value ($53.92 per 1,000 cleaning units ($737.63, 13,680) vs $83.15 per 1,000 cleaning units ($1,397, 16,800)).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every gas pressure washer; a clear win is highlighted. How we rank explains each one.
| Factor weight | Westinghouse WPX3800 | Simpson Aluminum 4200 PSI |
|---|---|---|
| Overall rating | 4.0/5 | 3.4/5 |
| Value 35% | 54 $53.92 per 1,000 cleaning units ($737.63, 13,680) | 8 $83.15 per 1,000 cleaning units ($1,397, 16,800) |
| Cleaning power 30% | 100 13,680 cleaning units (3,800 PSI x 3.6 GPM) | 100 16,800 cleaning units (4,200 PSI x 4 GPM) |
| Hose 10% | 100 35 ft hose | 100 50 ft hose |
| Warranty 25% | 50 3-year warranty | 50 3-year warranty |
Specifications
| Westinghouse WPX3800 | Simpson Aluminum 4200 PSI | |
|---|---|---|
| Cleaning | ||
| Pressure | 3,800 PSI | 4,200 PSI |
| Flow | 3.6 GPM | 4 GPM |
| Cleaning units | 13,680 | 16,800 |
| Nozzles included | 5 | 5 |
| Detergent | Onboard tank | - |
| Power | ||
| Power | Gas | Gas |
| Engine or motor | 274 cc (Westinghouse OHV) | 389 cc (Honda GX390) |
| Pump | Triplex plunger | Triplex plunger |
| CARB compliant | No | No |
| Build | ||
| Hose | 35 ft | 50 ft |
| Weight | 91 lb | 133 lb |
| Warranty | 3 years | 3 years |