Ideal oil for classic cars

Discover How to choose the ideal oil for classic cars and protect your engine. Key tips and practical recommendations.

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That day I understood that oil can save or destroy your classic engine.

I'm not going to lie to you...

For years, I thought the oil issue was a minor one. That as long as I changed the lubricant on time, any brand would do, after all... oil is oil, right?

Well let me tell you that I was completely wrong. And I didn't realize it until I almost destroyed the engine of my beloved 1967 Mustang.

Yes, I admit it. I put in modern synthetic oil thinking I was getting the best out of it.

And what happened next made it clear to me that when it comes to classic cars, Choosing the right oil is not an option, it is a necessity.

Today I'll tell you what I learned (the hard way) about this topic, how it impacts engine performance and life, and what oil you should use depending on your favorite vehicle.

Maintenance of specific components

MAINTENANCE

Why modern oil can be an enemy for classic cars

When you've been in this business for years, you realize that classic cars have souls... and they also have very different needs than modern cars.

Here is the first great truth:

Modern oils are designed for new engines, with closer tolerances, different parts, and systems that didn't exist in the 1960s, 1970s, or 1980s.

Do you know what happened when I put that synthetic oil in my Mustang?

• The engine began to make a slight metallic tapping sound.
• I noticed small leaks where there was nothing before.
• The oil pressure was weird, unstable.

After taking it to a specialized mechanic, he dropped the bomb on me:
"Brother, your engine isn't made for synthetic oils. It can destroy soft metals, seals, and conventional components."

That's when I really got into researching how lubricant actually works in a classic.

How oil works in a classic engine

Oil isn't just a lubricating fluid. It's a shield. It protects parts, prevents wear, maintains stable temperatures, and traps impurities.

But classic engines have particularities:

• Wider tolerances: They need more viscous oils to maintain the protective film.
• Use of soft metals: such as lead or copper, which are sensitive to certain modern additives.
• Lack of synthetic seals: Old seals cannot withstand the detergents or solvents in some modern oils, causing leaks.

And here a key element appears: zinc (ZDDP).

The additive that saves your engine: ZDDP

Older oils had high levels of ZDDP (Zinc Dialkyl Dithiophosphate). This compound is essential for protecting high-pressure parts, such as camshafts, rocker arms, and camshafts.

The problem?

Due to environmental regulations, modern oils have greatly reduced their ZDDP content.

Result?
If you use modern oil in a classic, that engine isn't getting the wear protection it needs.

How to choose the ideal oil for classic cars

✅ 1. Choose the right viscosity

Classic engines require higher viscosities.

• 15W-40 or 20W-50 are the most recommended, depending on the climate and the model.
  If you live in a very cold place, you can go with 10W-40, but be careful… it depends on the engine.

✅ 2. Prioritize oils with high ZDDP content

Look for classic car-specific lubricants that clearly state their zinc content.

Brands I use and recommend:

• Valvoline VR1 Racing (high ZDDP)
• Driven Racing Oil HR Series
• Motul Classic Oil
• Lucas Hot Rod & Classic

✅ 3. Avoid synthetic oils (with exceptions)

Unless your engine has been rebuilt with modern components (current seals, metals, and materials), synthetic can cause:

• Leaks
• Loss of pressure
• Wear on soft metals

✅ 4. Use additives if you can't find the right oil

In some countries it is difficult to find oil with ZDDP.
In that case, you can add zinc additives, such as:

• ZDDPlus
• Lucas Zinc Additive

What happens if I use the wrong oil?

I don't want to scare you... but I'm telling you from the heart: you can destroy your engine.

• Accelerated cam wear.
• Wear on flat camshafts (very common in older V8s).
• Leaks in seals and retainers.
• Loss of compression.
• Metallic tapping.

And the worst part… sometimes you don't notice it until the damage is irreversible.

What oil do I use in my cars?

I'll tell you without a filter:

• 1967 Mustang (V8 289): Valvoline VR1 20W-50 mineral.
• Classic Porsche 911: Motul Classic 15W-50, which is specifically designed for engines from the 70s and 80s.
• 1969 Chevrolet Camaro: Lucas Hot Rod & Classic 10W-40 when in cold weather and 20W-50 in summer.

I have never touched a synthetic in an engine that has not been updated.

Oil change: how often?

Here's another myth I debunked.

While modern cars can go 10,000 km or more, in classic cars the rule is clear:
Every 5,000 km or once a year, whichever comes first.

And if you don't use your car much, you should still change it annually. Oil degrades over time, accumulates moisture, and loses properties.

Mistakes I'd never make again (and neither should you)

• Buying “the cheapest.” A rookie mistake.
• Thinking, "If it's good for a new car, it's good for mine." False.
• Ignore the oil's technical data sheet.
• Do not ask specialists or clubs of your model.
• Let more than a year go by without change.

Oil is the liquid soul of your classic engine

I learned the hard way that oil is just as important as fuel or spark plugs.

Choosing the right lubricant can mean the difference between enjoying your classic car for decades... or blowing the engine and crying your eyes out afterward.

If you love your machine as much as I love mine, I'll tell you this from the bottom of my heart: don't skimp on the oil. It's the lifeblood of the engine.

And if this article helped you, share it with your fellow classic-lovers.

Let me know in the comments what oil you use, any questions, or your experience. Let's learn together, brother.