10 bestOil Leak Additivesof June 2025
112M consumers helped this year.
5% off
1
STP Engine Stop Leak for Petrol & Diesel Engines 300 ml, Improved Concentrated Formula, Conditions your Engine and Prevents Minor Oil Leaks, Mechanical Car Cleaning Products, Made in the UK
STP
9.8
10% off
2
Wynn's Engine Oil Stop Leak - Prevents & Stops Oil Leaks - Restores Elasticity of Seals & O-Rings - Lubricates & Protects Engine Seals - Safe for All Engine Oils - 325ml
Wynn's
9.6
3
Wynn's Stop Smoke For Oil Additive For Reducing Petrol & Diesel Engine Exhaust Emissions and Engine Oil Stop Leak Sealer Treatment Additive For All Engine Types 325ml
Wynn's
9.5
28% off
4
LIQUI MOLY Oil Additive | 200 ml | Oil additive | SKU: 7178
Liqui Moly
9.3
6% off
5
Bar's Products OS-1-4PK Oil Seal (Engine Oil Burning/Leak Repair)
Bar's Leaks
9.0
7% off
6
Lucas Oil 10278 Engine Stop Leak, 946 ml
Lucas Oil
8.8
7
ATP AT-205 Re-Seal Stops Leaks Fast In Engines & Transmissions - English & French 236ml
ATP Automotive
8.5
8
LIQUI MOLY Pro-Line Oil Loss Stop | 1 L | Oil additive | SKU: 5182
Liqui Moly
8.2
9
LIQUI MOLY Pro-Line Gear Oil Leak Stop | 500 ml | Oil additive | SKU: 5199
Liqui Moly
7.9
10
Wynn's Professional Formula Engine Oil Stop Leak Sealer Treatment Additive 325ml
Wynn's
7.7
A Guide to Selecting the Best Oil Leak Additives
Choosing the right oil leak additive can be crucial for maintaining the health and performance of your vehicle. Oil leak additives are designed to stop or reduce oil leaks in your engine by rejuvenating seals and gaskets. When selecting an oil leak additive, it's important to understand the key specifications and how they align with your vehicle's needs. Here are some important factors to consider when choosing an oil leak additive.
Compatibility
Compatibility refers to whether the oil leak additive can be used with the type of oil and engine in your vehicle. This is important because using an incompatible additive can cause more harm than good. Additives are generally designed for specific types of oil, such as synthetic, conventional, or high-mileage oils. To navigate this, check your vehicle's manual for the recommended oil type and ensure the additive is compatible with it. If you have a high-mileage vehicle, look for additives specifically formulated for such engines.
Seal Conditioning
Seal conditioning is the additive's ability to rejuvenate and restore the flexibility of engine seals and gaskets. This is crucial because over time, seals can become brittle and shrink, leading to leaks. Additives with good seal conditioning properties can help extend the life of these components. When evaluating this spec, look for products that specifically mention seal conditioning or rejuvenation. If your vehicle is older or has high mileage, prioritize additives with strong seal conditioning capabilities.
Viscosity
Viscosity refers to the thickness of the oil after the additive is mixed in. This is important because the right viscosity ensures proper lubrication and protection of engine components. Additives can alter the oil's viscosity, so it's essential to choose one that maintains the recommended viscosity for your engine. To navigate this, check your vehicle's manual for the recommended oil viscosity and select an additive that will not significantly alter it. If you live in a region with extreme temperatures, consider how the additive might affect oil performance in those conditions.
Additive Concentration
Additive concentration indicates the amount of active ingredients in the product that work to stop leaks. This is important because a higher concentration can be more effective but might also be more aggressive on engine components. To navigate this, look for products that provide information on the concentration of active ingredients. If you have a minor leak, a lower concentration might be sufficient, whereas a more severe leak might require a higher concentration.
Ease of Use
Ease of use refers to how simple it is to add the product to your engine oil. This is important because a product that is difficult to use can lead to improper application and ineffective results. To navigate this, look for additives that come with clear instructions and are easy to pour into the oil reservoir. If you are not very experienced with car maintenance, prioritize products that are marketed as user-friendly.
Effectiveness Time
Effectiveness time is the duration it takes for the additive to start working and show results. This is important because you want to know how quickly you can expect the leak to stop. To navigate this, check the product label or reviews for information on how long it typically takes to see results. If you need a quick fix, look for additives that are known for their fast-acting properties. If time is not a critical factor, you might opt for a product that works more gradually but is gentler on the engine.
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