Why Balance Matters in Motor Oil: Too Much of a Good Thing Can Hurt Your Engine

 Why Balance Matters in Motor Oil: Too Much of a Good Thing Can Hurt Your Engine

When it comes to engine oil, it’s tempting to believe that more is better—more ZDDP, more viscosity, more additives. But this mindset can lead to engine damage instead of protection. In truth, the key to effective lubrication isn’t excess—it’s balance.

In this second installment of the “Five Things You Should Know About Oil” series, Lake Speed Jr.—a member of the Society of Tribologists and Lubrication Engineers (STLE)—explains why finding the right blend of oil properties is crucial for engine performance and longevity.

ZDDP (zinc dialkyldithiophosphate) is one of the most well-known anti-wear additives in motor oil. But while ZDDP is critical for protecting flat-tappet cams and other high-load parts, too much ZDDP can actually increase wear. More isn’t always better.

The same is true for oil viscosity. An oil that’s too thick can starve vital components of lubrication, especially during cold starts or at high RPM. Similarly, overfilling your crankcase can lead to oil churning, increased operating temperatures, and foam—aerated oil—which offers little to no protection.

Then there’s the temptation to “fix” a perceived oil deficiency with aftermarket additives. This approach often does more harm than good. Mixing incompatible chemicals can reduce the oil’s effectiveness, especially when using high-ZDDP supplements with oils not designed for them. As Speed warns, that’s like playing chemical Russian Roulette with your engine.

The bottom line? Use an oil designed for your specific application. A properly engineered lubricant doesn’t need extra help from aftermarket products. It already contains the optimal balance of additives, viscosity, and detergents for its intended use.

If you’re unsure which oil is right for your vehicle, consult with an expert or a trusted brand like Driven Racing Oil. Their lubricants are developed for real-world engines—whether it’s a street-driven Porsche or a high-RPM race build.