PennGrade Motor Oil: The Original Green Oil That Keeps Engines Running Smooth

When it comes to protecting high-performance and classic engines, not all motor oils are created equal. One name that continues to stand the test of time is PennGrade® Motor Oil—often referred to as “The Original Green Oil.” With a rich heritage and a loyal following among racing pros and restoration experts, PennGrade offers a unique blend of history, innovation, and performance.

A Legacy That Runs Deep

PennGrade Motor Oil traces its roots back to Brad Penn Lubricants, based in Bradford, Pennsylvania—right in the heart of where America’s oil industry began. The oil is refined from Pennsylvania Grade crude oil, a uniquely pure and paraffinic base stock known for its excellent natural lubricity, film strength, and thermal stability.

PennGrade became especially popular after the original Kendall refinery (later purchased by American Refining Group, Inc.) continued the tradition of producing this iconic green oil—earning a reputation as the go-to choice for vintage and performance engines.

Why the Green Color?

If you’ve ever poured PennGrade oil, you’ve probably noticed its distinctive green hue. That’s not just for looks—it's a visual indicator of the brand’s unique formulation and commitment to tradition. The color also helps mechanics and engine builders quickly identify it during service.

Performance Where It Counts

PennGrade is a high-zinc, high-phosphorus motor oil, making it especially suitable for:

• Classic cars with flat-tappet camshafts

• Muscle cars and hot rods

• Dragsters and racing engines

• Vintage motorcycles and air-cooled engines

The high levels of ZDDP (zinc dialkyldithiophosphate) provide superior wear protection, particularly critical in older engines where modern low-zinc oils can fall short.

Key Benefits of PennGrade Oil:

✅ High film strength – Prevents metal-to-metal contact under extreme stress
✅ Excellent thermal stability – Performs well under high temperatures
✅ Natural detergency – Keeps engines cleaner for longer
✅ Strong anti-wear protection – Especially for flat-tappet and high-RPM engines
✅ Consistent performance – Trusted by professional engine builders and racers alike

Modern Engines vs. Classic Engines: Why It Matters

Many modern motor oils have reduced zinc content due to stricter environmental regulations and the introduction of roller camshafts in newer engines. While this is great for emissions systems, it can spell disaster for older engines that rely on zinc for wear protection.

Using the wrong oil in a classic or high-performance engine can lead to premature wear or even catastrophic failure. That’s why so many enthusiasts stick with PennGrade—it offers old-school protection with modern reliability.

 

Popular PennGrade Products

From monograde oils to semi-synthetic blends, here are some standout variations:

• 10W‑40 Semi‑Synthetic Racing Oil : High-zinc blend designed for maximum protection during spirited engine use. 

• 20W‑50 Semi‑Synthetic Racing Oil : A go-to high-viscosity option for hot climates or high-RPM engines. 

• 50W Conventional High‑Zinc Oil : Thick oil for older engines or harsh operating conditions. 

• 30W Conventional High‑Zinc Oil : Straight-grade classic oil ideal for break-in or traditional engine builds. Complete Street Performance

• Motorcycle Series (10W‑40 & 20W‑50): Specifically tailored for motorcycle engines, offering conventional blends optimized for spirited riding.

Who Uses PennGrade?

From weekend warriors restoring 1960s muscle cars to professional racing teams pushing engines to the redline, PennGrade has earned trust across the board. It’s especially popular in:

• NHRA drag racing

• Circle track and dirt track racing

• Vintage restoration communities

• Air-cooled Porsche and VW circles