Modern automatic transmissions are more complicated than their predecessors. Today's designs feature more gears, clutch packs and narrow oil passageways that require a steady supply of high-quality fluid.

High-Quality Assembly Lube for Racing, Performance and Other Four-Stroke Engines AMSOIL Engine Assembly Lube (EAL) is formulated to cling to engine parts and provide exceptional wear protection, while inhibiting rust and corrosion in newly built or rebuilt four-stroke engines. It is designed to dissolve in oil, helping eliminate oil port clogging and deposit formation.

Engineered for enthusiasts seeking maximum protection and performance. Precision-formulated with cutting-edge technology and a longstanding devotion to making the world's best motor oil. The result: engine protection that blows the doors off the highest industry standards.

AMSOIL Signature Series Synthetic Motor Oil delivers extraordinary lubrication in all types of automotive gasoline engines.

AMSOIL Synthetic 10W-40 Motor Oil is specially formulated to provide superior protection and performance in a wide variety of demanding applications.

Recommended for up to 300whp.

Recommended for up to 450whp

Recommended for up to 600whp

Formulated without friction modifiers to allow for quick and efficient piston ring seating in new and rebuilt high-performance and racing engines. Contains zinc and phosphorus anti-wear additives to protect cam lobes, lifters and rockers during the critical break-in period when wear rates are highest.

High-performance engines run at extreme temperatures and under intense stress, particularly if they are turbocharged. The added heat and pressure invites engine wear and formation of harmful sludge if the oil isn’t formulated for this intense environment.