10 Best Oil Additives To Stop Leaks 2025 in the United States

The Lucas Oil 10009 Transmission Fix is a highly regarded transmission problem-solving additive designed to stop leaks and extend the life of transmission fluid. One of its major strengths is that it does not contain solvents, making it a safer option for your vehicle's internals. You can easily add it to your existing transmission fluid without the need to drain any out, which is convenient and saves time.

This product is especially effective for motor homes and commercial vehicles, and it can extend the life of your transmission fluid up to four times longer, reducing the need for frequent fluid changes. It also offers additional protection to planetary gears and improves shifting ease in worn transmissions. However, it's important to note that it is not recommended for CVT transmissions and dual-clutch vehicles.

Be mindful that in larger or heavily worn transmissions, you may need to use a second bottle for optimal results. For smaller vehicles, a smaller 12 oz. bottle is recommended. With its strong market presence, Lucas Oil 10009 Transmission Fix is a reliable choice for those looking to maintain or improve their vehicle’s transmission performance.

Lucas Oil Products LUC10278 Engine Oil Stop Leak is designed to address oil leak issues in vehicles. It's compatible with a variety of automotive systems, making it a versatile choice for many users. One of its key strengths is its effective seal conditioning, which helps rejuvenate old and worn seals to prevent leaks. Additionally, it includes viscosity modifiers, which help maintain optimal oil thickness for better performance and leak prevention.

The product also contains detergents and dispersants, ensuring that the engine remains clean and free from deposits that could cause further leaks or damage over time. With a high additive concentration, it promises a potent formula that can deliver noticeable results quickly. This product is primarily designed for UTV (Utility Task Vehicles), which might limit its applicability for other vehicle types. The one-quart packaging is sufficient for a single treatment, but users with larger engines or more severe leaks might need multiple bottles.

Weighing just over 2 pounds and with compact dimensions, it's easy to handle and store. Manufactured in the United States by Lucas Oil Products, a well-known and reputable brand in the automotive industry, it offers a reliable solution to common oil leak problems. Users should ensure their vehicle type matches the product's specifications for the best results.

Bar's Leaks Jack Oil with Stop Leak - 12.5 oz is designed to stop current leaks and prevent future ones, making it a practical solution for maintaining floor and bottle jacks as well as snow plow fluids. This product stands out due to its compatibility with all types of petroleum-based, mineral oil, and synthetic fluids, which means you won't have to worry about compatibility issues. The non-corrosive, non-clogging, and non-foaming properties ensure it won't damage your equipment or create additional problems during use.

While it ranks well in its category (#59 in Engine & Oil Fluid Additives), it is not the top product, indicating there may be other additives with higher performance or additional features. Additionally, the emphasis on its anti-wear properties suggests its primary function is to prevent wear and tear rather than to clean or disperse contaminants. This might not be the best option if you are looking for a multi-functional additive that also cleans. Bar's Leaks Jack Oil is a reliable choice for those specifically looking to address and prevent leaks in hydraulic systems.