Gasoline oxygenated with MTBE can be pipelined to wherever. Gasoline with an ethanol oxygenate has to be blended near the point of sale, and cannot be sent down the pipeline pre-blended because the ethanol absorbs water and the line will corrode.
Much lower transport costs with MTBE.
Aha, correct. Thanks for pointing that out. It was odd to me why a complex compound like MTBE would be chosen over simpler ethanol, that explains it.