Has anyone else wondered if one brand is more efficient than another? Suppose you're facing a three day blackout, and want to power a 1000W average load. How many gallons of gas will you need? Materials: 1 generator (keep outdoors when operating) 1 kw-hr meter 1 space heater (on extension cord if you want heat somewhere) This will only test up to 1.5 kw loads since those cheap kw-hr meters are limited in the power they can handle. Warm up the generator and let it run out of gas. Add exactly one quart of gasoline. Plug in the meter, and plug the space heater into the meter. Start the generator, and wait. I tested one Made in China 1000W unit, and was disappointed that it only made about 1 kw-hr out of a quart of gasoline. That's barely 10% efficiency. A small engine should make at least 20% mechanical energy. Is the alternator really losing 50% to heat?