Generators are having a moment. Specifically, portable gas generators are undergoing a technological makeover that dramatically boosts their level of performance. So if you're looking into getting one, you'll want to consider an inverter generator. They come at a premium—and also with great advantages.

An inverter generator electronically throttles the engine up and down to meet demand, instead of running full tilt all the time. The resulting improvement in efficiency means that, for the same size gas tank, you won't have to fill it up as often. An inverter generator produces lower emissions, and it is very quiet.

"You can carry on a conversation next to an inverter generator," says Dave Trezza, who oversees CR's generator testing.

All of which explains why so many new models are popping up at home centers and online.

A New Class of Generator

To help you make better sense of your options, CR has revamped the categories for generator ratings, adding a new one for inverter generators. We break them up into three groups:

1. Large
With very few exceptions, the large inverter generators in our ratings weigh around 250 pounds or more (wheels included). That's too big to haul along to a tailgate, and just big enough to power your house: They generate 5,000 watts of power or more (at 220 volts). This category of inverter generator can be connected directly to your electrical panel with a safety device called a transfer switch, which CR strongly recommends.

2. Midsized
These weigh 80 pounds or more, and may or may not come with wheels. They produce 2,500 to 4,500 watts but don't allow the recommended option of connecting to your electrical panel with a transfer switch. Instead, you plug appliances or electronics directly into the generator, which can be dangerous if you don't follow certain guidelines.

3. Recreational
These weigh 50 to 60 pounds, and are designed to be carried with one hand. Most recreational models max out at around 2,000 watts, which should be plenty for tailgating or camping. Don't let the size lull you into a false sense of security, though: They still emit carbon monoxide, which can kill you at high enough concentrations, and should never be operated inside an enclosed space.

CR Tests Inverter Generators

More on generators

Consumer Reports recently wrapped up testing on 12 new models. These machines range in capability from the compact type you’d want for a tailgate or camping trip to something that could be a steady source of basic backup power after a storm. Here, we've picked three of those newly tested models—one from each new category—to highlight the different sizes you'll see in inverter generators, and call out who will be best served by each. 

For the Tailgate

Yamaha EF-2000is v2
Price: $1,000
Power output: 1,600 watts
Run time: 5 to 11 hours
Weight: 53 pounds
CR's take: The Yamaha EF-2000is v2 is lean and compact, and produces a steady 1,600 watts of power. It also burns only 2 to 6 gallons of gas per day to do it. At 53 pounds, it's light enough to tote to a football game, the beach, or a campsite, which is exactly what recreational generators are designed for. It's obviously not what you'd try to use to power your house after a storm, but for outdoor activities, it's enough to charge phones or power speakers, and it's quiet enough that you'll actually be able to hear your companions while it's running. It's one of the only generators in our ratings to earn the best score possible for noise. 

For the Occasional Power Outage

Kohler PRO 2.8i
Price: $1,650
Power output: 2,500 watts
Run time: 8 to 18 hours
Weight: 83 pounds
CR's take: Like the best midsized stationary generators, this Kohler hits the sweet spot of being lightweight enough to take on a camping trip yet robust enough to provide real relief after an occasional outage. With 2,500 watts, you can power a space heater, a window air conditioner, or a fridge, along with a series of fans and lights. Those are all tasks that require a steady source of reliable power, and in our demanding tests, that's exactly what the Kohler delivered. It's not what you'd want if outages are routine in your area, but if you're largely using it recreationally, you'll be glad to have it if a downed tree limb knocks out your power for a few days. 

For Frequent Power Outages

Honda EU7000is
Price: $4,000
Power output: 5,500 watts
Run time: 8 to 16 hours
Weight: 292 pounds
CR's take: This Honda exemplifies what a larger inverter generator can do. It puts out as much power as most of the conventional portable generators in our ratings but uses less gas than any of them, and runs quieter, too. You can plug appliances directly into the tool, but it's meant to be connected to a circuit breaker panel with a transfer switch or interlock device. If you live in an area prone to power outages, this model can run a well pump, water heater, and most heating systems, along with essentials like lights and fans. Like most of the inverter generators in our ratings, the Honda gets excellent marks for power delivery and quality—the two tests we perform to see how well a generator responds to big swings in demand as appliances and fixtures kick on and off.