This study investigates the compatibility of nitrile butadiene rubber (NBR) with pyrolysis oil from used tires. Pyrolysis oils are obtained by thermal treatment of shredded tire waste under oxygen free conditions. Oils are gained from truck, car, and bicycle tires. As a blending component for conventional diesel fuel, the oils are intended to prevent the shortage of fossil raw materials and contribute to ensuring the supply of fuels. When used as fuel, the mixtures come into contact with elastomer materials such as nitrile butadiene rubber. In order to provide a damage-free use of blended fuels in established systems, the compatibility of the elastomers with the fuels must be guaranteed. For this purpose, the diesel fuel and pyrolysis oil compositions was first analyzed using IR spectroscopy. Second the diffusion behavior of diesel-pyrolysis oil fuels in NBR is investigated using sorption tests by immersing them in the respective fuels. After specific time periods, the mass, density and mechanical properties of the NBR are recorded. It turns out that pyrolysis oil has a higher proportion of aromatic compounds than diesel fuel. As one result, the mass of NBR in pyrolysis oil increases more, and the mechanical properties are more strongly influenced than those of NBR stored in diesel fuel.