Moisture in gasoline is a big problem for lawn mowers, generators and other equipment powered by gasoline engines, said Scott Wesenberg, manager of Briggs & Stratton's fuel systems group. A manufacturer of small gasoline engines, Briggs & Stratton has created its own fuel additive that it says offsets some of the negative side effects of ethanol, including the very common moisture problem.

According to Briggs, ethanol tends to get messy, and water in the gasoline is often the culprit. The company says the biofuel additive ethanol, which is contained in much of the gasoline people buy today, can attract moisture out of the air like a magnet.

The additive doesn't eliminate ethanol in gasoline, it displaces water and keeps ethanol from gumming up an engine's fuel system. There are other fuel additives that displace water and keep gasoline fresh in storage, but Briggs says it's the first engine maker to develop its own formula that does those things and more.

However, backers of ethanol say the problems Briggs cites are exaggerated. “Don't blame ethanol for water in gasoline,” says Kristy Moore, vice president of technical services for the Renewable Fuels Association.  According to Moore, most of the problems stem from careless handling of fuel, such as leaving the cap off a gasoline can and failing to use a fuel stabilizer when outdoor power equipment is put in storage for months. "We call these 'housekeeping issues,'" she said. "If someone doesn't take care of equipment to keep water out of the fuel, they're going to have a hard time starting that engine."

Briggs' fuel additive was designed to offset some of the problems with a 10% ethanol blend in gasoline engines but wasn't meant to address E15, which has begun to creep into the marketplace.