Reminiscent of Ghostbuster's Marshmallow Man, new Goodyear tires might just Stay-Puft on their own. The company is developing Air Maintenance Technology (AMT) tires with built-in pumps to keep themselves at the perfect pressure. The reason? Even slightly under-inflated tires can drop your mileage by 3.3 percent, costing you cash at the pump. For highway-hustling commercial trucks that's a whole lot of moola, leading the US Department of Energy's Office of Vehicle Technology to grant Goodyear $1.5 million towards self-plumping commercial tire development. For those of us who don't wear mesh hats,
