Snake Oil or Science? Testing the Claims of Oil Additives

You know the drill. You're staring down a classic build, maybe a V8 hot rod, and you're doing the final tune-up. Everything seems dialed in—the headers are perfect, the carb is jetted, the bore and stroke are spot on. You've got the perfect blend of gas, and the engine sings. But then, the marketing department rolls in with the next big thing: a bottle of oil additive that promises to cut down on internal friction by 50% and boost your MPG.

As gearheads, we’re skeptical. We know the difference between legitimate mechanical improvement and pure snake oil. Do these additives really make a difference in the cylinder walls, or are they just marketing hype designed to get you to spend cash on the shelf?

The claims around molybdenum disulfide (MOS2) and other chemical compounds are wild. We’re talking about things that supposedly create a protective, low-friction film that keeps your lifters, pistons, and crankshaft spinning happier and longer. But do the numbers back it up? We decided to take a deep dive, running a controlled test to see if this product could actually improve engine performance under load.

Testing the Additives: It's All About the Numbers

To properly evaluate a product like this, you can't just eyeball it. You need measurable data. We set up a controlled test using a small engine, running through cycles designed to test two main things: lubricity and fuel economy. The process is mechanical, not magical.

First, we had to ensure the test was apples-to-apples. We cleaned up the combustion chamber and got everything dialed in. The goal was simple: run the engine, measure the RPMs and the fuel consumption, and then repeat the process after adding the additive. If the claims are true, the metrics—the RPMs and the fuel burn—should change.

The test was rigorous. We used a specialized lubricity tester to compare the film strength of the additive against conventional oil. Then, we hooked up a generator to measure the fuel efficiency under a consistent load. The data is what matters, not the flashy packaging.

The Takeaway: Grease Under the Fingernails

When you've run the numbers, inspected the scoring on the test bearings, and compared the output under load, the picture becomes clearer. While oil additives can contain valuable ingredients—like paraffin oils and molybdenum disulfide—the real-world impact on a properly maintained engine is something that needs proof, not just a fancy fact sheet.

As DIY mechanics and project car enthusiasts, we rely on proven mechanics. We respect the science, but we demand the data. If you're planning a major build, whether it's an LS swap or a full restoration, stick to proven practices and quality components. If you're doing a daily driver tune-up, trust your instincts and your tools.

Want to see what the shop floor looks like? We’re always on the hunt for new projects. If you've got a basket case, a rotisserie build, or a custom service to offer, drop us a line. Find a Master Mechanic near you, list your project car, or book a CrownRunner for parts—let's get wrenching.