Electric pressure washers and gas pressure washers differ significantly in terms of power and efficiency. 
Electric pressure washers typically offer pressures ranging from 1,300 to 2,000 PSI (pounds per square inch) and are generally suitable for light to medium-duty tasks such as cleaning cars, patios, and outdoor furniture. They are powered by electricity, making them more environmentally friendly and quieter than gas models. Electric models are also more efficient for smaller tasks due to their ease of use, lower maintenance requirements, and the absence of fuel storage needs. They are ideal for residential use where power outlets are readily available.
Gas pressure washers, on the other hand, provide higher power levels, often ranging from 2,000 to 4,000 PSI or more, making them suitable for heavy-duty tasks like stripping paint, cleaning large areas, and tackling tough stains. They are powered by gasoline engines, which makes them more portable and suitable for use in remote locations without access to electricity. However, gas models are typically noisier, require more maintenance, and involve handling fuel, which can be less convenient.
In terms of efficiency, electric pressure washers are more energy-efficient for smaller jobs and are easier to start and operate. Gas pressure washers, while less energy-efficient, offer superior cleaning power and speed for larger, more demanding tasks. The choice between the two depends on the specific needs of the user, with electric models being more efficient for smaller, routine cleaning tasks and gas models being more efficient for larger, intensive cleaning projects.