Tips, modes or a dial: how each unit changes pressure
- Swap-in nozzle tips only. The Sun Joe SPX3000 and the Simpson MSH3125 each ship five quick-connect tips at 0°, 15°, 25°, 40° and a soap setting. Neither publishes a variable pressure dial.
- Selectable power modes. The EGO HPW3200 has ECO, High and Turbo modes on a handheld control, with a 15°, 25°, 40°, turbo and rinse nozzle set on top of that.
- A dial on the gun. The Generac 7132’s PowerDial gun adjusts pressure at the trigger, and it also takes quick-change tips.
With tips only, the pressure a surface receives depends on remembering to fit the right tip before you pull the trigger, every time. A mode switch or a dial gives you a second thing to check. This is why pressure control carries the heaviest weight in this guide’s scoring, ahead of PSI itself.
Flow: which GPM figure applies
EGO publishes two flow figures in the HPW3200 manual: 2.0 GPM (7.5 L/min) with only the short pressure gun connected, and 1.2 GPM (4.5 L/min) with the quick-connect lance and stainless wand attached. The wand configuration is the one you would stand over a driveway with, so the figure that applies to driveway work is 1.2 GPM, the same as the Kärcher.
Sun Joe’s figure depends on which page you read. Sun Joe’s current SPX3000 product page lists 1.2 GPM and a 13-amp motor. The Amazon listing for the SPX3000-SJB in this guide lists 1.76 GPM and a 14.5-amp motor. The two cannot be reconciled from the documents retrieved, so the comparison table carries both and the flow score reflects the conflict rather than either number.
Multiplying PSI by GPM gives a rough way to compare across power types. It is arithmetic on two ratings, not a measurement:
| Unit and configuration | PSI × GPM |
|---|---|
| Simpson MSH3125 | 3,200 × 2.5 = 8,000 |
| Generac 7132 | 3,100 × 2.5 = 7,750 |
| EGO HPW3200, short gun only | 3,200 × 2.0 = 6,400 |
| EGO HPW3200, lance and wand | 3,200 × 1.2 = 3,840 |
| Sun Joe SPX3000, Amazon listing figure | 2,030 × 1.76 = 3,573 |
| Sun Joe SPX3000, Sun Joe’s page figure | 2,030 × 1.2 = 2,436 |
| Kärcher K1700 | 1,700 × 1.2 = 2,040 |
The two gas units land at roughly twice the EGO’s wand-attached figure, and between three and four times the two corded units on their manufacturers’ own flow ratings. The EGO with the short gun alone sits between the groups. That is the configuration its 2.0 GPM figure describes, and not the one most driveway work uses.
Matching the machine to the surfaces you actually have
If the car and the deck are the regular jobs and the driveway is occasional, the two corded units cover it. The Kärcher gives you three nozzles rather than five, a published weight of 15.5 lb, a 0.3 gal onboard detergent tank, a foot switch, and a built-in storage bin for cord and hose. The Sun Joe carries two 0.9 L detergent tanks, a 20-ft high-pressure hose and a 35-ft GFCI cord, and its Total Stop System shuts the pump off when the trigger is released.
If the driveway is large, sloped, or a long way from an outlet, the Simpson is the unit built around that job, and its 66 lb weight is the cost.
If the car is parked where no cord reaches and you do not want fuel or exhaust near the garage, the EGO is the only cordless option here, rated for up to 60 minutes on a charge with two 6.0Ah batteries, with IPX5 ingress protection when the battery compartment is closed and a foam cannon included. Count the battery purchase as part of the decision, because the HPW3200 SKU does not include them; the HPW3204-2 kit does.
If the dial is the feature you want, the Generac is the only unit that has one. You cannot compare its weight or pump against the others from any published document.
When the corded electric is genuinely enough
On flow, a corded electric gives up nothing to the EGO in the configuration you would use on a driveway: all three publish 1.2 GPM, the EGO specifically with its wand attached, taking Sun Joe’s own page figure. The gap is in pressure, 1,700 and 2,030 PSI against 3,200, and in the cord. Sun Joe publishes a 35-ft GFCI cord; the Kärcher page retrieved does not state a cord length. If every surface you clean is within reach of an outlet, the corded units publish 24.3 lb and 15.5 lb, and the Kärcher carries a 3-year warranty against the Sun Joe’s 2.
Where corded is not enough is the driveway that is the main reason you are buying. If you are buying for the driveway first and the car second, the Simpson’s published figures match that order; the corded units’ figures do not.
What the spec sheets leave out
Warranty terms vary more than the PSI figures do. EGO publishes a 5-year tool warranty, the longest here. Kärcher publishes 3 years, Sun Joe 2. Simpson’s breakdown of 2 years engine, 1 year pump, 5 years frame and 90 days accessories comes from a secondary source and was not confirmed on Simpson’s own warranty document. No warranty term for the Generac appears in the documents retrieved.
Two inlet conditions are worth reading before you connect a hose. The EGO publishes a 145 PSI maximum water inlet pressure and a 41°F to 104°F (5°C to 40°C) recommended operating temperature. The Kärcher publishes a 104°F maximum water feed temperature and an integrated inlet water filter. The other three do not publish inlet limits in the documents retrieved.
Cord, battery or fuel: what each one commits you to
The two corded units run on 120V household power. Sun Joe specifies a 13-amp, 2000W motor on its product page, with the Amazon listing for this ASIN stating 14.5 amps; Kärcher specifies a 120V/60Hz universal motor. The EGO needs two 56V ARC Lithium batteries, and its 60-minute runtime figure is for a pair of 6.0Ah packs; no runtime for other battery sizes appears in the sources retrieved.
The Simpson starts on a pull cord. The Generac starts on a push button powered by a removable lithium-ion battery, with a pull cord as backup, and is CARB compliant.
