Automotive

For engine oil and the higher temperatures of the engine bay, FKM (Viton®) is the standard — it holds up to +200 °C and resists oils and fuels. At lower temperatures, or where better mechanical resistance is needed, choose HNBR. Ordinary NBR is suitable only for cooler locations and standard oils, not the hot part of the engine.

DOT 3/4/5.1 brake fluids are glycol-ether based, and NBR swells and degrades in them. EPDM is compatible with these fluids and is therefore the standard for brake systems. Note: EPDM, conversely, must NOT contact mineral oil — so it is never used in the same assembly as oil seals.

For petrol and diesel, FKM is the most reliable long-term, resisting fuels and additives. With biofuels (FAME/biodiesel), ordinary NBR hardens and cracks — choose HNBR (lower FAME share) or FKM (full resistance). Always account for the temperature around the fuel line as well.

Yes, if you choose the right material. HNBR covers roughly −40 to +150 °C and suits most engine and fuel applications. FKM handles higher temperatures (up to +200 °C) but stiffens at very low temperatures — for cold starts, check the compound's lower temperature limit. For extreme cold, special low-temperature FKM and silicone compounds exist.