AMSOIL Signature Series Multi-Vehicle Synthetic Automatic Transmission Fluid is engineered for demanding automatic transmissions operating under heavy loads, high temperatures and severe service. It provides durable wear protection, excellent friction performance and strong resistance to thermal breakdown while maintaining excellent fluidity in cold conditions.

Towing, hauling, stop-start driving and challenging terrain can generate substantial heat inside an automatic transmission. Elevated temperatures accelerate fluid degradation and can contribute to sludge, varnish and wear. Modern transmissions make fluid performance particularly important, with multiple clutch packs, narrow fluid passages and precisely controlled hydraulic systems relying on clean, stable transmission fluid.

Proven in Severe-Service Fleet Testing

AMSOIL evaluated Signature Series Multi-Vehicle Synthetic ATF in Las Vegas taxi cabs operating in demanding stop-and-go service, carrying passengers and cargo in high ambient temperatures. After accumulating 180,000 miles (approximately 290,000 km) of severe-service operation, a transmission was selected for analysis.

Independent laboratory testing found that the used fluid continued to demonstrate strong oxidation resistance after the field trial. Internal transmission components, including the valve body and clutch plates, were also found to be virtually free of damaging sludge, deposits and wear.

Resists Heat and Thermal Breakdown

High transmission temperatures can accelerate oxidation and cause conventional fluid to deteriorate. Signature Series Synthetic ATF is formulated with a robust antioxidant system to resist thermal breakdown and help prevent the formation of sludge and varnish that can interfere with narrow fluid passages and contribute to clutch glazing.

Following the 180,000-mile severe-service field trial, fluid analysis showed Signature Series Multi-Vehicle Synthetic ATF retained 83% of its original oxidation inhibitors, demonstrating substantial reserve protection after prolonged severe use.

Outstanding Wear Protection

Automatic transmissions subject gears and bearings to varying speeds, loads and high torque. Signature Series Synthetic ATF combines high film strength with anti-wear and extreme-pressure additives to help protect critical components under severe operating conditions.

In the FZG Gear Wear Test, Signature Series Multi-Vehicle Synthetic ATF taken from the 180,000-mile field trial achieved a pass at Stage 12, the highest test stage. The used fluid exceeded the Ford MERCON V and Chrysler ATF+4 wear requirements cited by AMSOIL for new fluid.

Long-Lasting Friction Performance

Modern automatic transmissions depend on carefully controlled friction characteristics for smooth clutch engagement and reliable torque transfer. Signature Series Synthetic ATF is formulated with friction modifiers designed to provide strong clutch-holding capacity, effective dynamic friction and anti-shudder performance in slipping torque-converter clutches.

Analysis following the 180,000-mile severe-service trial found the used fluid retained friction characteristics close to those of new Signature Series Multi-Vehicle Synthetic ATF, helping support smooth, consistent shift performance throughout extended severe service.

Excellent Cold-Temperature Fluidity

Automatic transmission fluid must also flow readily when cold. Thick fluid can slow hydraulic response and increase energy losses during warm-up. Signature Series Synthetic ATF provides excellent low-temperature fluidity to promote rapid circulation, responsive shifting and efficient operation in cold conditions.