Mid-Size Portable Generators

4,000- to 8,000-watt portable generators

Midsized generators are most often used to power essential appliances during emergencies, as well as on job sites. Generators in the 4,000- to 8,000-watt class will provide enough power for a refrigerator, lighting and at the higher end, a small, window air-conditioning unit.

In this size range, reviews recommend a couple of Briggs & Stratton models that can be converted into multifuel portable generators (handy when gasoline isn't available). The 6,200-watt Briggs & Stratton Elite 30242 (*Est. $1,000) gets very high ratings based on comparison tests, and owners posting reviews at ElectricGeneratorsDirect.com give it top marks. It surges to 8,750 watts, and automatic voltage regulation protects appliances from power surges. If you don't need an electric starter or quite that much power, the 5,500-watt Briggs & Stratton Elite 30241 (*Est. $800) surges to 8,550 watts. This model doesn't have automatic voltage regulation. It gets enthusiastic owner-written reviews at both Amazon.com and ElectricGeneratorsDirect.com. Both Briggs & Stratton generators have 7-gallon fuel tanks, five outlets, automatic low-oil shutdown, and carry two-year warranties.

The 5,500-watt Generac 5736 (*Est. $750) gets above-average ratings from owners posting reviews at ElectricGeneratorsDirect.com and at Northern Tool and Equipment. They report that the Generac 5736 starts easily and runs for over eight hours on a tank of gas. This generator provides surge power up to 6,875 watts, and has automatic low-oil shutoff, maintenance alert resets and covered GFCI outlets. Portability features include fold-down handles and "never-flat" wheels. This and other Generac generators earn a Good Housekeeping Seal and are covered by a two-year Good Housekeeping warranty in addition to the two-year manufacturer coverage. California residents will want to look at the Generac 5737 (*Est. $830) -- a CARB-certified version of the 5736.

The 5,500-watt, electric-start Honeywell HW5500E (*Est. $850) surges to 6,875 watts and has automatic low-oil shutoff, automatic voltage regulation and overload protection. A manual-start version, the HW5500 (*Est. $780) is available, as is a CARB-compliant version, the HW5500EL (*Est. $950), and a manual-start, CARB-compliant version, the HW5500L (*Est. $850). All the Honeywell generators have three-year warranties. A larger Honeywell electric-start model, the 7,500-watt HW7500E (*Est. $1,000), gets good user reviews from owners posting at Amazon.com and ElectricGeneratorsDirect.com. Its surge capacity is 9,375 watts, and it has the same features as the aforementioned HW5500E. There's also a CARB-compliant version: the HW7500EL (*Est. $1,100). User-reviewers appreciate that both the HW5500E and the HW7500E include a 30-amp extension cord that would normally retail for around $100.

Whole-house generators, 10,000 to 17,500 watts

You can get portable generators in even larger sizes, but these might be overkill if you just want a backup generator to keep your fridge running during occasional power outages.

For even higher wattages -- to power an all-electric home, for example -- we saw some support for Generac generators, though it's hard to find reviews on models in this size range. The Generac 5734 and 5735 GP Series generators provide enough power to run most household lights and appliances plus a central heating or air-conditioning system, but you'll need to purchase and install a transfer switch to provide power to systems and devices that are not plugged in but connected directly to your breaker box.

The 15,000-watt Generac 5734 (*Est. $2,400) surges to 22,500 watts, while the 17,500-watt Generac 5735 (*Est. $2,700) provides up to 26,250 surge watts. Each features an electric starter, full-pressure lubrication and automatic low-oil shutoff. A 16-gallon gas tank provides about 10 hours of runtime at half load. With auto-idle turned on, the engine adjusts to one-fourth, one-half, three-fourths or full-load wattage. Both models are powered by Generac's overhead valve industrial (OHVI) engine, which meets California emissions standards. Since they're part of the GP Series, these big Generac generators come with two-year factory warranty coverage, plus an additional two-year Good Housekeeping warranty.