Located directly between Green Bay and Milwaukee, Quality State Oil is in a good spot to fill up when you're driving through Wisconsin. The company operates a chain of 21 Q Mart gas stations from which it sells BP, Citgo, Exxon Mobil, and Shell gasoline. Quality State Oil operates its own fleet for distribution and supplies gasoline, diesel, Mobil lubricants, kerosene, heating oil, and fuel oil throughout northeast Wisconsin. The company also has three bulk plants, which have the capacity to store a half-million gallons of fuel.