In a head-to-head, 100,000-mile test, AMSOIL Signature Series provided excellent wear protection and kept bearings looking like new.

See the Proof

Signature Series Synthetic Motor Oil

  • 50% more cleaning power vs. AMSOIL OE Synthetic Motor Oil
  • Ideal for turbos & direct injection
  • Guaranteed protection for up to 25,000 miles or 1 year
  • Available in 5W-30, 0W-20, 5W-20, 0W-30, 10W-30, 0W-40 and 5W-50 viscosities
Buy Now

Proven Wear Protection

Your bearings shoulder the burden whenever you tow, haul or stomp the gas. AMSOIL delivers powerful protection for bearings and other critical components. An independent lab compared Signature Series head-to-head against a leading competitor in a 100,000-mile test. Signature Series provided far superior wear protection and kept bearings looking like new.* Upgrade to AMSOIL performance and drive with confidence.

Find Products for your vehicle

Engine Builders Love AMSOIL

"If you have a car that you really love, you want to take care of it. That’s why I recommend AMSOIL."

~ Daniel Boshears, engine builder and Chief Mechanic at the Wellborn Musclecar Museum

Watch Now

Enthusiasts Love AMSOIL

"This is a great fully synthetic oil that never disappoints… I can run this oil for extended drain intervals and not worry one bit."

~ Stephen, Foxworth, Miss.

*Testing conducted in an independent lab using AMSOIL Signature Series 5W-30 Synthetic Motor Oil and a leading synthetic-blend 5W-30 motor oil in Ford F-150 trucks with 3.5L twin-turbo engines.