Democratic politicians say the drop has coincided with the start of a Federal Trade Commission investigation into price-fixing by oil companies.
Republicans say the market forces of supply and demand are at work.
8333 W. Layton Ave., Hales Corners. Wittig and Ciecka also say their business has picked up, although they haven't won back all the customers they lost when the price shot up. Gas prices started rising nationwide earlier this year as the Organization of Petroleum Exporting Countries slapped new limits on production. Pump prices then jumped sharply in the Milwaukee and Chicago areas after June 1, when federal environmental rules required a new blend of cleaner-burning reformulated gas. Although reformulated gas is required in 17 metropolitan areas nationwide, only Milwaukee and Chicago rely exclusively on an ethanol version.