Excerpt: When we dove into the Pennzoil XLF Showdown: comparing Longevity, the 1-gallon (3-pack) Marine Extended Life Formula caught our attention. Packaging three gallons of oil into one convenient bundle offered us a surprising value, blending affordability with marine-grade protection. We were particularly impressed by its synthetic chemistry, designed to resist breakdown under heavy loads, ensuring our engines stayed lubricated for thousands of miles. Less frequent oil changes translated to fewer trips to the marina, saving us time and money. While we’ve tested other synthetic oils, Pennzoil XLF delivered consistent performance without unnecessary trade-offs. The extended drain interval didn’t just cut costs—it aligned with our desire for a no-frills, worry-free maintenance routine. For boaters prioritizing longevity and efficiency, this 3-pack stands out as a smart, practical choice.