(a) Except as provided in paragraph (b) of this section or otherwise in the provisions of this Subpart I, the 15 ppm sulfur content standard of §80.520(a) shall apply to all motor vehicle diesel fuel at any downstream location.

(b) Prior to the October 1, 2010 and December 1, 2010 dates specified in §80.500(d)(3) and (4), the 500 ppm sulfur content standard of §80.520(c) shall apply to motor vehicle diesel fuel at any downstream location, provided the following conditions are met:

(1) The product transfer documents comply with the requirements of §80.590, including indicating that the fuel complies with the 500 ppm sulfur standard for motor vehicle diesel fuel and is for use only in model year 2006 and older diesel motor vehicles, or the fuel is downgraded pursuant to the provision of §80.527 to motor vehicle diesel fuel subject to the 500 ppm sulfur standard;

(2) The motor vehicle diesel fuel is not represented or intended for sale or use as subject to the 15 ppm sulfur content standard, and is not dispensed, or intended to be dispensed, into model year 2007 and later motor vehicles by a retailer or wholesale purchaser-consumer; and

(3) For retailers or wholesale purchaser-consumers, the pump labeling requirements of §80.570(a) are satisfied.