DIRT BIKES HAVE MORE POWER from smaller engines but hold a minimal amount of oil. Better have a good oil that not only protects the engine against heat but protects the clutch against wear and slippage. AMSOIL ‘DIRT MOTORCYLE OIL” exceeds all of the requirements for the extreme conditions created by the high revving engines of dirt bikes. AMSOIL is not a redesigned automotive but designed by working with professional supercross and motorcross riders. THEN tested under the most severe summer heat conditions.