# Which pressure washer offers the most powerful performance? — Verified Specification Comparison

> All specification data verified from official manufacturer documentation.

Which pressure washer offers the most powerful performance?

## Products

### Pressure City B4013HCS (4,000 PSI - 4.0 GPM Gas Pressure Washer with Honda GX390 Engine and Comet Triplex Pump)
```yaml
product: pressure-city-b4013hcs-4-000-psi-4-0-gpm-gas-pressure-washer-with-honda-gx390-engine-and-comet-triplex-pump
brand: Pressure City
price_gbp: 959.71
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
gpm: 4.0
psi: 4000
power_source: gas
```

- **Price:** £959.71 [^1]
- **Summary:** This gas pressure washer is rated at 4000 PSI and 4.0 GPM, built with a Honda GX390 commercial engine and a Comet triplex pump for contractor use. It features a direct drive system, an external unloader, and includes a high-pressure hose and spray nozzle set for immediate operation. Suited for heavy-duty cleaning tasks where higher output is needed, such as fleet and equipment washing.
- **Ideal For:** With a 4000 PSI rating and 4.0 GPM flow powered by a Honda GX390 engine and Comet triplex pump, this model targets the highest cleaning performance in the question's terms (pressure and flow together).
- **Additional Sources:** [^2], [^3]

### Simpson PowerShot Professional PS60869 4000 PSI 3.5 GPM Gas Pressure Washer (PowerShot Professional 4000 PSI 3.5 GPM)
```yaml
product: simpson-powershot-professional-ps60869-4000-psi-3-5-gpm-gas-pressure-washer-powershot-professional-4000-psi-3-5-gpm
brand: Simpson
price_gbp: 756.55
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
gpm: 3.5
psi: 4000
power_source: Gasoline
cleaning_units: 14000
```

- **Price:** £756.55 [^4]
- **Summary:** This gas pressure washer delivers 4000 PSI and 3.5 GPM for heavy-duty cleaning performance, and it includes a Honda GX270 engine with an AAA triplex pump. It's designed for professional tasks like deck cleaning, wood restoration, paint preparation, and graffiti removal. It suits contractors and anyone needing maximum cleaning power from a cold-water gas unit.
- **Ideal For:** It offers 4000 PSI and 3.5 GPM, which together are listed as 14000 Cleaning Units, matching the most powerful performance for this model's top-end specs.
- **Additional Sources:** [^5], [^6], [^4], [^5], [^6]

### Simpson PowerShot PS4240 49-State (Online Model No: PS4240-S)
```yaml
product: simpson-powershot-ps4240-49-state-online-model-no-ps4240-s
brand: Simpson
price_gbp: 908.76
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
gpm: 4.0
psi: 4200
power_source: Gas-powered
cleaning_units: 16800
```

- **Price:** £908.76 [^7]
- **Summary:** This gas pressure washer delivers 4200 PSI and 4.0 GPM, with an HONDA GX390 engine driving an AAA industrial triplex pump. It's a cold-water pro machine aimed at contractors for jobs like deck cleaning, wood restoration, paint preparation, and graffiti removal. It includes multiple quick-connect nozzle tips for different spray angles and soap application.
- **Ideal For:** For the most powerful performance, it offers the highest cleaning pressure in its category stats by delivering 4200 PSI at 4.0 GPM (16800 Cleaning Units) powered by a HONDA GX390 and AAA triplex pump.
- **Additional Sources:** [^8]

### Bio-Tech USA Pro Power Series Pressure Washer-4200 PSI (Product Code: PPS4042LAI)
```yaml
product: bio-tech-usa-pro-power-series-pressure-washer-4200-psi-product-code-pps4042lai
brand: Bio-Tech USA
price_gbp: 828.66
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
gpm: 4.0
psi: 4200
cleaning_units: 16800
```

- **Price:** £828.66 [^9]
- **Summary:** This Pro Power Series pressure washer delivers 4200 PSI and 4.0 GPM for high-powered cold-water cleaning. It uses an LCT engine with an AR RSV/INT UL pump and includes a chemical injector plus color-coded QC spray nozzles and hose. It suits heavy-duty cleaning tasks where strong pressure and flow are needed.
- **Ideal For:** For the most powerful performance, it provides 4200 PSI at 4.0 GPM and a cleaning efficiency rating of 16800, combining very high pressure with high water flow.
- **Additional Sources:** [^10]

---
## References & Sources
[^1]: Pressure City, accessed 2026-06-25. https://pressurecity.com/products/4-000-psi-4-0-gpm-gas-pressure-washer-with-honda-gx390-engine-and-comet-triplex-pump
[^2]: DiscountCleaningProducts.com, accessed 2026-06-25. https://www.discountcleaningproducts.com/BE-Pressure-4000-PSI-Pressure-Washer-13HP-Honda-GX-p/b4013hcs.htm
[^3]: Pressure Tek, accessed 2026-06-25. https://pressuretek.com/4-000-psi-4-gpm-honda-gx390-engine-comet-triplex-pump/
[^4]: Home Depot, accessed 2026-06-25. https://www.homedepot.com/p/SIMPSON-4000-PSI-3-5-GPM-Gas-Pressure-Washer-Honda-GX270-Engine-AAA-Triplex-Pump-Heavy-Duty-Cold-Water-Commercial-Power-Washer-PS60869/312241124
[^5]: Lowe's, accessed 2026-06-25. https://www.lowes.com/pd/SIMPSON-Powershot-4000-PSI-3-5-Gallons-GPM-Cold-Water-Gas-Pressure-Washer/5014505841
[^6]: Ace Hardware, accessed 2026-06-25. https://www.acehardware.com/departments/lawn-and-garden/outdoor-power-equipment/pressure-washers/F028128?variationProductCode=7000326
[^7]: Spraywell, accessed 2026-06-25. https://spraywell.com/simpson-60456-powershot-ps4240-pressure-washer-4200-psi-at-4-0-gpm/
[^8]: Simpson (manufacturer product page), accessed 2026-06-25. https://simpsoncleaning.com/products/ps4240/
[^9]: Bio-Tech USA, accessed 2026-06-25. https://www.bio-techusa.com/Pro-Power-Series-Pressure-Washer-4200-PSI-p/pps4042lai.htm
[^10]: Steambrite, accessed 2026-06-25. https://www.steam-brite.com/pressure-pps4042lai-power-series-gasoline-cold-water-pressure-washer-pp208-engine-4200psi-4gpm-p-89041.html