Opinion ID: 455926
Heading Depth: 2
Heading Rank: 4

Heading: Materials Compatibility and Driveability

Text: 62 Finally, petitioners argue that the Administrator erred in concluding that Petrocoal does not present materials compatibility or driveability problems. See Brief for MVMA at 49-56. The Administrator observes in the Petrocoal waiver decision that both materials compatibility and driveability are important criteria in evaluating a waiver request. See Petrocoal Waiver, 46 Fed.Reg. at 48,977. Materials incompatibility can contribute or cause the failure of vehicles to meet either their exhaust or evaporative emission standards ... because a fuel ... may cause changes in the components in carburetors or fuel systems which exceed the tolerances specified by the manufacturer. Id. Driveability information is important because poor driveability can directly result in increased emissions due to constant misfires and repeated stalling, and possibly lead to tampering with the emission controls of the vehicle. Id. The Administrator concluded that based on the information developed in the record that Petrocoal presented neither materials compatibility problems nor significant driveability problems affecting emissions. 63 Since we have already found on the basis of petitioners' other challenges that the Administrator acted arbitrarily, capriciously, and abused her discretion in granting the Petrocoal waiver, we find it unnecessary to determine expressly whether the Administrator also acted arbitrarily and capriciously in concluding that Petrocoal resulted in no significant materials compatibility or driveability problems. 26 We are compelled, however, to express our doubts about the adequacy of the Administrator's findings with respect to materials compatibility problems. The EPA, itself, has recognized that materials compatibility is a particularly salient concern with methanol blends. See supra p. 394. Yet, the record data on materials compatibility problems associated with Petrocoal is rendered suspect by the lack of any unequivocal evidence that the effects of the worst case fuel allowed by the waiver were ever tested. See supra p. 397. Nor do we find the mere presence in Petrocoal of a proprietary inhibitor, which purportedly inhibits materials compatibility problems, a sufficient basis for concluding that materials compatibility will not be a problem in the absence of data supporting the actual effectiveness of the inhibitor. 27