Smith-Bell Petroleum, a business in Gainesville for about 80 years, introduced a new fuel alternative Thursday when the company has installed its first unattended tank for propane autogas. Autogas is an alternative fuel that Jay Fulenwider, Pacific Pride marketing director, said is used by commercial fleets of vehicles, businesses with one or two vehicles or even an individual who drives a lot, for example 65,000 or 70,000 miles a year. The fuel is an additional offering at a Pacific Pride station at 2312 Monroe Drive, which also offers unleaded gas, clear diesel and off-road diesel fuel.