Z-ROD® 20W-50 Synthetic Motor Oil Modern Technology For Classic Cars A high-zinc formulation to prevent wear on flat-tappet camshafts and other critical engine components.
I recently bought a 55 Thunderbird and thankfully the engine was low mileage since the last rebuild because the owner was using a standard NAPA conventional 10W-40. I got ZROD in there just in time I hope! (oil analysis to follow). Unless it’s diesel oil which doesn’t contain the ideal ZDDP levels and subsequent additive package for seals and other issues, it’s a better bad choice. But the regular modern API rated oils will eventually cause severe wear on your cams and lifters. Avoid that and aftermarket additives at all costs.
AMSOIL Z-ROD Synthetic Motor Oil is specially engineered for classic and high-performance vehicles. It features a high-zinc formulation to prevent wear on flat-tappet camshafts and other critical engine components, along with a proprietary blend of rust and corrosion inhibitors for added protection during long-term storage. Z-ROD 20w-50 Synthetic Motor Oil is designed to perform on the street and protect during storage.
The lifters and cam lobes on flat-tappet camshafts common to classic and high performance vehicles slide rapidly against one another, producing high friction and heat. The friction between the two components can eventually wear down the cam and affect valve operation, ultimately resulting in lost engine power and reduced efficiency. In addition, these areas are splash-lubricated rather than pressure lubricated like other areas of the engine, which adds extra strain on anti-wear additives like the zinc and phosphorus in zinc dialkyldithiophosphate (ZDDP).
AMSOIL Z-ROD Synthetic Motor Oil is formulated with high levels of ZDDP to protect flat-tappet cams, lifters, rockers and other areas susceptible to wear. Its high-zinc, high-phosphorus formulation provides the extra wear protection these critical splash-lubricated components require.
Download the updated ZROD Line Data Sheet
Download PDFProduct Datasheet
AMSOIL Z-ROD 20w-50 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. The metal coupon treated with AMSOIL Z-ROD Synthetic Motor Oil showed no signs of oxidation after 192 hours, while the coupon treated with a leading competitor’s product failed the test after 24 hours.
AMSOIL Z-ROD Synthetic Motor Oil is recommended for older or modified engines requiring either 10W-30, 10W-40 or 20W-50 motor oil. Z-ROD Synthetic Motor Oil meets API SL and earlier specifications, allowing for increased levels of anti-wear additives. ZDDP levels in Z-ROD Synthetic Motor Oil exceed the limits of API SM and newer specifications.
AMSOIL Z-ROD Synthetic Motor Oils are compatible with conventional and other synthetic motor oils. Mixing AMSOIL Z-ROD Synthetic Motor Oils with other oils, however, will shorten the oil’s life expectancy and reduce the performance benefits. Aftermarket oil additives are not recommended for use with AMSOIL Z-ROD Synthetic Motor Oils.
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.
HEALTH & SAFETY
This product is not expected to cause health concerns when used for the intended application and according to the recommendations in the Material Safety Data Sheet (MSDS). An MSDS is available via the Internet at www.amsoil.com or upon request at (715) 392-7101. Keep Out of Reach of Children. Don’t pollute. Return used oil to collection centers.
For warranty information, visit www.amsoil.com/warranty.aspx.
By GLENN, a Verified Buyer from Orlando, FL on April 14, 2025
After much research and thought I finally decided to switch to synthetic motor oil last year in my 1979 Corvette with a 350 crate engine with low mileage. There had been several oil leaks from the engine area but after running Amsoil Z-Rod, the leaks all stopped. I used it with the Wix oil filter. This year I did the annual oil change and still no leaks and the engine actually purrs differently from previously without the Amsoil. I am a believer.
By DON, a Verified Buyer from Apopka Florida on February 11, 2025
This motor oil is just what my numbers matching 1970 El Camino Custom needed! Idle smoothed right out, motor noise is less and oil pressure is right where it should be. My new Comp Cam is saying thank you!!!
By ANTHONY, a Verified Buyer on October 11, 2024
I use this oil in a Ford Cleveland 408 stroker and my 66 Mustang GT 289 A- code engine. After a refresh on the stroker, I literally could have reused the bearings. This is 550+ hp street engine that gets drove like it’s supposed to. I use Amsoil in everything I drive. Also, broke in the 408 on the Dyno with the Amsoil break in oil.
By GURTAJ, a Verified Buyer on May 25, 2024
This stuff is perfect for protecting my big block with a flat tappet cam. Really quality oil here, I don’t use any other brand in my vehicles!
By MARK, a Verified Buyer from Buffalo on January 23, 2024
Using on my 1963 Buick Skylark. Needed Earl Wiff Some ZiNK. In it. And eYe Noticed that it was Smooth Right after the oil change… i could notice a difference, seemed Smooth… hard to explain but I feel it does a little smother right after an earl change. Best oil for your Flat Tappett Cam.
By AL, a Verified Buyer from Arkansas on January 08, 2024
In the early days when I was building custom cars and street rods there weren’t roller camshafts so the oil had ingredients to protect flat tappet camshafts, along came Catalytic converters so oil companies removed the Zink & Phosphorus from their oil as they destroyed Catalytic Converters!!!!!! Most all classic cars restored don’t have a Catalytic Converter, but need an oil with Zink & Phosphorus tp protect there camshafts during break-in and after that as well!!! Z-Rod has these ingredients in it!!!!!
By Jack , a Verified Buyer from Upstate NY on December 31, 2023
I decided to use this for the winter storage months. Will be using the AMSOIL regular synthetic for the warmer driving months.
A must upgrade for Polaris Rangers is our indestructible 100% Synthetic 0W-50 UTV and ATV oil The way a lot of our customers use their ATV’s demand proper lubrication and cooling when most competitor oils sheer out. Why pay more for an oil that isn’t the viscosity you paid for after a few uses? You […]
1968 Chevrolet C10 Pickup Truck Wins GM Design Award for Truck of the Year Kerry Johnson |Mar 17, 2017 4:30 PM The SEMA Show is the place to see and be seen in the automotive scene. A no-holds-barred display of custom car builds, as well as the latest and greatest in the automobile aftermarket, SEMA really […]
