The compatibility of fueling infrastructure elastomers in bio-oil and diesel fuel was determined by measuring the volume swell and hardness before and after drying. The bio-oil was produced via fast pyrolysis from a blend of pine feedstocks. The elastomer materials included two fluorocarbons, six acrylonitirile butadiene rubbers (NBRs), fluorosilicone, styrene butadiene rubber, neoprene, polyurethane, neoprene, silicone, ethylene propylene diene monomer (EPDM), hydrogenated acrylonitrile butadiene rubber (HNBR), a blend of NBR and PVC (OZO), and a blend of epichlorohydrin and ethylene oxide (ECO). The majority of the elastomer materials (except for EPDM, SBR and silicone) exhibited higher volume expansion in bio-oil than in diesel. Excessive swelling was noted for the polyurethane, neoprene and three of the NBRs. In general, the higher polarity of these elastomers more closely aligned with the polarities of the bio-oil versus the diesel fuel. Conversely, EPDM, SBR, and silicone are relatively nonpolar and this matches the low polarity of the diesel fuel, which resulted in higher volume expansion in diesel, rather than the bio-oil for these four polymers.