A method is disclosed for preparing an elastomeric base composition comprising: (I) mixing (A) a fluorocarbon elastomer with (B) a compatibilizer, (C) an optional catalyst, (II) mixing the product of step (I) with (D) a silicone base comprising a curable organopolysiloxane, (E), an optional crosslinking agent, (F) a cure agent in an amount sufficient to cure said organopolysiloxane; and (III) dynamically vulcanizing the organopolysiloxane, wherein the weight ratio of fluorocarbon elastomer (A) to silicone base (B) in the elastomeric base composition ranges from 95:5 to 30:70. The cured rubber compositions obtained from the elastomeric base compositions herein have good fuel resistance properties.