FFV vehicles operated on E-85 require specially formulated engine oils. These special requirements are included in MOPAR engine oils, and in equivalent oils meeting Chrysler Specification MS-6395. The manufacturer only recommends engine oils that are API Certified and meet the requirements of Material Standard MS-6395. MS-6395 contains additional requirements, developed during extensive fleet testing, to provide additional protection to Chrysler Group LLC engines. Use MOPAR or an equivalent oil meeting the specification MS-6395.