
AAA PowerBoost
Score: 88/100
CAT 67DX
Score: 85/100Rankings

The AAA 3700 PSI pump is a high-performance triplex replacement featuring brass heads and ceramic pistons for superior durability and cleaning power. Its adjustable unloader and thermal protection make it a robust choice for heavy-duty tasks. It is best suited for DIY homeowners or semi-pros with gas pressure washers needing a reliable, long-lasting upgrade.

The CAT Pumps 67DX39G1I is a high-performance direct-drive triplex plunger pump delivering 4000 PSI at 3.9 GPM, ideal for professional surface cleaning. Its adjustable unloader and chemical injector offer significant versatility, though it is limited to cold water use. It is best suited for horizontal shaft gas engine setups utilizing 1-inch SAE J609 flange mounts.
| Attribute | ![]() | ![]() |
|---|---|---|
3,700 PSI | 4,000 PSIbest | |
2.5 GPM | 3.9 GPMbest | |
0.75 inches | 1 inchesbest | |
12 inchesbest | — | |
3,600 RPMbest | 3,450 RPM | |
0.75 inchesbest | 0.5 inches | |
— | 0.375 inchesbest | |
0.063 quarts | 0.423 quartsbest |
Click an attribute name to sort · Green = best, red = worst (relative to this comparison)
| Attribute | ![]() | ![]() |
|---|---|---|
Performance(3) | ||
Maximum Pressure (PSI) | 3700 PSI | 4000 PSI |
Flow Rate (GPM) | 2.5 GPM | 3.9 GPM |
Operating RPM (RPM) | 3600 RPM | 3450 RPM |
Compatibility & Mounting(4) | ||
Shaft Diameter (inches) | 0.75 inches | 1.0 inches |
Shaft Type | Horizontal | Hollow |
Inlet Port Size (inches) | 0.75 inches | 0.5 inches |
Outlet Port Size (inches) | M22 inches | 0.375 inches |
Durability & Maintenance(2) | ||
Seal System | Advanced Oil Seal | NBR |
Oil Capacity (quarts) | 0.0625 quarts | 0.423 quarts |
Physical(1) | ||
Product Weight (lbs) | 9.0 lbs | 17.0 lbs |
Features & Control(1) | ||
Unloader Type | Adjustable Hand Knob | Integral Adjustable |


Products in the top-left offer the best value (high score, low price).

Professional reviewers praise the pump for surpassing expectations in harsh conditions, highlighting the PowerBoost technology and easy-start unloader.
Users appreciate the easy oil checks, adjustable power, and quick setup, noting robust build quality and compatibility with popular engines like Honda GX200.

Manufacturer documentation emphasizes the pump's reliability for pressure washing, highlighting the triplex plunger design for high efficiency and low pulsation. The direct-drive capability is noted for eliminating the need for pulleys, belts, and gearboxes, while retail specifications point out the ease of servicing and CARB approval.
No consumer reviews, praise, or complaints were found in the search results. Official documents imply suitability for demanding use through durable components, but no real-world user data is available to assess everyday sentiment.
