Scientists have gotten oil down to a science. Depending on the application, engine oil can have totally different formulas, weights, and additives, mixed and matched to deliver the most efficiency, longevity, or performance. That's why you should only use the oil your engine was designed to use, even if a better oil exists.
Lake Speed Jr. of The Motor Oil Geek YouTube channel explains why in a video, showing the wear effects between three different types of oil. He explains that while a racing oil like Valvoline's VR-1 might still have all the correct properties to match (or even exceed) the factory-recommended oil, it's still not smart to run it over the same interval.
All modern synthetic motor oil has a certain amount of antioxidants, or high-temperature stabilizing additives. This allows the oil to stay effective over a period of time without going bad from use or age. Street car oils have far more of these additives, making them viable for 10,000- or 15,000-mile oil change intervals. Speed Jr. says racing oils don't have nearly the same amount, meaning they won't last as long.
That's not a problem for racing applications, as the oil in competition motors is changed with far more frequency. But if you leave a racing oil in your street car for 10,000 miles, you'll actually subject your engine to more wear—even if the oil is higher-quality.
Speed Jr. likens racing oil to racing tires. Tires meant for racing have a softer compound, allowing them to deliver more grip. But the softer compound wears far quicker than, say, a harder, more lasting street tire with real tread.
So next time you consider swapping out your oil for the expensive race-specific stuff, think about your use case first. It might save you some expensive wear and tear.
