Liqui Moly Engine Oil Additive 3721 Concentrated Formula for Viscosity Stability & Deposit Reduction

Liqui Moly 3721 Engine Oil Additive is a concentrated formula designed to stabilize and protect engine oil, reduce deposits, and remain compatible with modern filter systems.

This concentrated oil additive from Liqui Moly enhances lubricant performance under heavy thermal and dynamic loads without requiring a core charge. It mixes with existing engine oil to help maintain viscosity stability, minimize sludge and deposits, and works safely with all commonly used oil filters. Ideal for routine oil maintenance, it offers a simple, drop-in solution for drivers wanting improved oil resilience and cleanliness between service intervals.

How does this additive help engine oil under high temperatures?

Under intense heat and mechanical stress, base oils can thin or oxidize, which accelerates wear and deposit formation. Liqui Moly 3721 contains thermal stabilizers and detergents that help preserve oil viscosity and prevent harmful residues from forming on vital engine parts.

• Thermal stability additives reduce viscosity breakdown at high temperatures.
• Detergent components help dissolve and suspend deposits for easier filtration.
• Compatible with modern synthetic and mineral oil blends to maintain performance.

Will it harm my vehicle’s oil filter or lead to blockages?

No — Liqui Moly engineered this product to be fully compatible with commonly used filter systems so it won’t promote clogging when used as directed. The formulation avoids creating additional residues and keeps particles suspended so the filter can capture them effectively.

• Tested for compatibility with standard engine oil filters.
• Formulated to avoid deposit buildup that could impede flow.
• Works with routine filtration to remove contaminants.

How do I add it to my engine oil and how much should I use?

Application is straightforward: add the recommended amount of Liqui Moly 3721 to the engine oil during an oil change or when checking oil level, following the product dosing instructions. Because it is a concentrated treatment, a single quantity treats a standard crankcase volume without requiring additional components or cores.

• Designed for simple pour-in application during oil service.
• Single-quantity packaging matches common crankcase sizes.
• No separate core charge or extra parts are needed.

What performance benefits should I expect between oil changes?

You can expect improved oil stability, fewer deposits, and better overall cleanliness of internal engine components when used as part of regular maintenance. While not a guaranteed fix for worn engines, it supports oil life and engine hygiene to help components function more smoothly.

• Reduced tendency for sludge and varnish on engine parts.
• Enhanced oil resilience under varying load conditions.
• Supports filtration and cleaner oil circulation throughout the crankcase.

Who is this for: Liqui Moly 3721 Engine Oil Additive is suited for vehicle owners and technicians seeking a professional-grade, easy-to-use oil treatment that improves lubrication stability and protects engine internals between services. It's practical for passenger cars, light commercial vehicles, and anyone wanting to maintain cleaner oil and reduce deposit formation without altering existing filter systems. Always follow your vehicle manufacturer’s recommendations and the product dosing directions for safe use.