AMSOIL now offers a synthetic motor oil engineered specifically for classic cars and performance vehicles. Available in 10W-30 and 20W-50 viscosities, AMSOIL Z-ROD Synthetic Motor Oil (ZRT, ZRF) features high-quality synthetic base stocks and a proprietary additive package tailored to perform on the street and protect during storage.

 

Vintage Vehicles Have Different Needs

As engine design has evolved over the past 50 years, oils have also evolved to meet these changing needs. Use of modern emissions regulation devices has resulted in the limitation of zinc dialkyldithiophosphate (ZDDP) content in motor oil. High amounts of phosphorus in ZDDP additives can negatively affect a vehicle's catalytic converter and reduce its effectiveness. However, ZDDP additives are proven, effective anti-wear agents that are especially important in classic and performance vehicles that feature flat-tappet camshafts and custom lifters and rocker arms for increased performance; the limitation of these additives in modern oils reduces the oil's effectiveness in classic and performance applications.

 

Protecting Flat-Tappet Cams

Two main types of camshafts are used in automotive applications: flat-tappet and roller. The tappet, or lifter, on the flat-tappet camshaft is flat and requires an oil film to keep its surface separated from the cam lobe. Flat-tappet camshafts produce high friction (high heat) because the surfaces slide rapidly against each other. The oil film is the only barrier that prevents the lifter and cam lobe from welding together. The friction between the two components can eventually wear down the flat-tappet cam and affect valve operation. Engine power and efficiency decline if the flat-tappet cams can't life the valves enough to adequately charge the chamber for ignition or adequately release exhaust fumes. In addition, these areas are splash-lubricated rather than pressure-lubricated like other areas of the engine putting extra strain on anti-war additives.

 

Z-ROD is Packed with ZDDP

AMSOIL Z-ROD Synthetic Motor Oil is formulated with high levels of ZDDP to protect flat-tappet cams, lifers, rockers and other areas susceptible to wear. Its high-zinc, high phosphorus formulation provides the extra wear protection these critical splash-lubricated components require.

 

Long-Term Protection from Rust & Corrosion

Rust and corrosion are the classic car owner's nemesis. Classic cars spend most of their existence in storage and only hit the road in the summer months. The rarity of these vehicles and their owners place extra importance on protection during extended periods of the storage. AMSIOL Z-ROD Synthetic Motor Oil is formulated with a unique blend of rust and corrosion inhibitors to ensure maximum protection during long-term storage. To prove its effectiveness, AMSOIL submitted Z-ROD Synthetic Motor Oil to the Standard Test Method for Rust Protection in the Humidity Cabinet (ASTM D-1748). This test evaluates the rust-preventative properties of oil under high-humidity conditions, similar to those faced by a covered hot rod in a damp garage. After 192 hours, the metal coupon treated with AMSOIL Z-ROD Synthetic Motor Oil showed no signs of oxidation, while the coupon treated with a leading competitor's product failed the test.

 

Applications

AMSOIL Z-ROD Synthetic Motor Oil is recommended for older or modified engines requiring either 10W30 or 20W50 motor oil. Z-ROD Synthetic Motor Oil meets API SL and earlier specifications, allowing for the increased levels of anti-wear additives. ZDDP levels in Z-ROD Synthetic Motor Oil exceed the limits of API SM and newer specifications.

 

Service Life

Because engines in classic cars, hot rods and other performance vehicles are generally modified, a universal oil drain interval recommendation for these applications cannot be given. Responsibility for determining the drain interval duration rests with the owner. As a general service guideline, the maximum drain interval for Z-ROD Synthetic Motor Oil should not exceed 5,000 miles or one year, whichever comes first. In heavily modified engines (e.g. forced induction, nitrous) the maximum drain interval should not exceed 3,000 miles or one year whichever comes first.