Section 1048.425 - What records must I keep?(a) Organize and maintain your records as described in this section. We may review your records at any time.(b) Keep paper records of your in-use testing for one full year after you complete all the testing required for an engine family in a model year. You may use any additional storage formats or media if you like.(c) Keep a copy of the written reports described in § 1048.420 .(d) Keep any additional records related to the procurement process. 67 FR 68347 , Nov. 8, 2002, as amended at 70 FR 40476 , July 13, 2005