As someone who worked for a "greedy, polluting" oil company when MTBE was mandated I can tell you that the oil companies were 100% against it. The oil companies notified the govt that MTBE would not reduce pollution & may actually add pollutants to the air-which has now been proven. (They did not anticipate ground water contamination.) However, the govt geniuses ruled against the oil companies & now are coming full circle.
Of course now they will require ethanol as an additive in an effort to pander to the farm belt. As a result, we will be subsidizing the farmers to grow the corn & then paying higher gas prices for the federally mandated ethanol additive. By the way, the oil companies have also stated that ethanol will not do anything to reduce pollution.