Z-ROD® 20W-50 Synthetic Motor Oil

Modern Technology For Classic Cars

Z-ROD® 20W-50 Synthetic Motor OilAMSOIL 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 Synthetic Motor Oil is designed to perform on the street and protect during storage.

AMSOIL, the leader in automotive synthetic lubrication, produced the world’s first API-qualified synthetic motor oil in 1972. Trust the extensive experience of AMSOIL, the First in Synthetics®, to do the best job protecting your engine.

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Buy & Check PriceAnd Container Size

Buy in the Omaha store at 84th & G or use this Online link to the Amsoil sale page if you are outside of the area. There’s not much more I can add to this one as it says it all so well here but our Omaha customers often mention other products they add a ZINC additive to enhance it for their early model car but why go through that motion when we have this and several other high zinc products which have other superior aspects such as the highest quality seal conditioners, corrosion resistance which is an exclusive trait to AMSOIL products and the performance which keeps customers coming back!

Protects Flat-Tappet Cams

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.

Provides Long-Term Protection from Rust & Corrosion

metal-coupot-amsoil-testAMSOIL 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. 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 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.


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.

Keep Out of Reach of Children. Don’t pollute. Return used oil to collection centers.

For warranty information, visit AMSOIL Warranty Information


Customer Comments:

20/50 z rod in my Dart
By Niles 1/8/2017

from Marysville. California

I drive my 68 Dart 2 dr sedan constantly !!!! Literally !!!! It is small block mild with 3 speed auto. And Z Rod Is All I run It Along With Synthetic oil filter and go air filter all AMS Oil Products!!! Recommend it to Everyone !!

How would you describe yourself?:
I’m a professional mechanic

What kind of vehicle/equipment do you have?:
68 Dart 2dr. sedan

Bottom Line
Yes, I would recommend this to a friend


Z-ROD 20w-50
By Tom 8/29/2016

from Maine

This oil has lots of ZDDP. To protect my Cam and lifters. The 20W-50 I like because l run it in my air cooled engine. Even on a hot day with the Engine at temp of 280′ I still have 30# of oil pressure. I also run Amsoil gear lube in the transaxle. I’m sold Amsoil products.

How would you describe yourself?:
I love my vehicles / toys

What kind of vehicle/equipment do you have?:
1964 Corvair powered Dune buggy.

Bottom Line
Yes, I would recommend this to a friend