Bottom Line

The Generac 6598 is one of the most powerful consumer-grade pressure washers you'll find. There are five nozzle tips, two detergent tanks, and large wheels for easy maneuvering. User reviews are good at most sites, though complaints about shipping damage pull down scores in some cases. The entire pressure washer is covered for one year, and the motor for two.

ProsStandout performance, One-pull start, VersatileConsHose feels stiff, Not CARB compliant

Breaking it down


Powerful sprayer hits hard and fast. With Its 8,370 cleaning-power rating (the PSI rating multiplied by the GPM rating), the Generac 6598 is one of the strongest residential pressure washers that Generac makes, and owners say the power is noticeable. Users report good performance on decks, boats, walkways, cars and siding, as well as mold and mildew stains. Mike Aletich, product expert at PressureWashersDirect.com, praises the quality of the oversized, 212-cubic-centimeter engine and axial cam pump, saying the machine should last many years. The gas motor is covered for two years, the rest of the power washer for one year.


Multiple nozzles for versatile cleaning. Reviewers almost universally praise the Generac 6598's many features. One of the most popular is its selection of five spray tips. Those tips add to the power washer's versatility as users can choose the one that delivers most suitable pressure for each job. The two onboard detergent tanks, which hold a generous three-quarters of a gallon each, are another plus. The power washer is not CARB complaint, however, so California residents will need to look elsewhere.

Ease of use

A breeze to handle and maneuver. Although it weighs nearly 70 pounds, the Generac 6598 is easy to maneuver, says Aletich. Users echo this sentiment, with some saying the upright design also makes the machine convenient to move from place to place and to store. There are 10-inch wheels, which help keep the machine balanced, and an easy-pull trigger on the spray gun. Many users call the one-pull start easy and reliable, and most say that switching nozzles is simple to do. We read a few scattered complaints that the plastic hose is too short or stiff. We also noted some complaints of issues right out of the box, plus some that say that inadequate packaging and handling resulted in pressure washers that were damaged in shipping. Those are not the norm, however, and most users at most sites are tickled pink with the 6598.

Our Sources

1. PressureWashers Direct.com

Generac 3100 PSI (Gas-Cold Water) Pressure Washer, Mike Aletich and contributors to PressureWashersDirect.com, As of July 2015

Product expert Mike Aletich recommends the Generac 6598, praising its quality, design and maneuverability. A good number of users (more than 170) have weighed in with their own take -- and most give it a thumbs-up; 93 percent say that they would recommend this power washer to a friend.

2. Lowes.com

Generac 3,100-PSI 2.7-GPM Cold Water Gas Pressure Washer with Generac Engine, Contributors to Lowes.com, As of July 2015

While the raw numbers are somewhat inflated by reviews that also appear at the manufacturer's web site, Lowes.com hosts more user reviews for the Generac 6598 than we spotted anywhere else -- more than 230 in total. Satisfaction is high, with a 4.6-star rating and 94 percent saying that they would recommend the power washer to a friend.

3. HomeDepot.com

Generac Model 6598 3100-PSI 2.7-GPM OHV Engine Axial Cam Pump Gas Powered Pressure Washer, Contributors to HomeDepot.com, As of July 2015

While there's not as much feedback at HomeDepot.com as at PressureWashersDirect.com or Lowes.com, satisfaction is similar. Following more than 60 reviews, the Generac 6598 earns a 4.4-star rating, and is recommended by 92 percent owners.

4. Amazon.com

Generac 3,100 PSI 2.7 GPM 212cc OHV Gas Powered Residential Pressure Washer, Contributors to Amazon.com, As of July 2015

The Generac 6598 gets almost as many reviews here as at HomeDepot.com, but overall satisfaction is a tad less than elsewhere with a 3.8 star rating. We noted complaints about issues with shipping damage that we did not see at other sites, plus some report that they received units that failed either immediately or in short order. Still, even here, most owners are pleased.