Red Line WaterWetter coolant additive — 12 oz 2-pack, improves heat transfer and corrosion protection

Red Line WaterWetter Super Coolant is a concentrated additive that improves water’s heat transfer and helps guard cooling systems against rust and deposits.

Designed for engines where peak cooling performance matters, this WaterWetter concentrate enhances the ability of plain water or diluted antifreeze to move heat away from the engine. It’s commonly used by racers, performance enthusiasts, and anyone seeking lower operating temperatures or reduced antifreeze concentrations in warm climates. The product works with glycol-based antifreezes and can be used with straight water in certain applications where corrosion control is still needed.

How does WaterWetter help engines run cooler?

WaterWetter lowers the surface tension of coolant, allowing liquid to more effectively contact and pull heat from metal surfaces. That improved wetting increases the efficiency of heat transfer across the entire cooling circuit, which can reduce peak temperatures under load.

• Contains a concentrated wetting agent formulated for heat transfer improvement
• Reduces localized hot spots by improving coolant contact with engine surfaces
• Suitable for use with straight water or reduced antifreeze mixtures

Will this product protect my cooling system from rust and corrosion?

Yes—WaterWetter includes corrosion inhibitors that allow the use of straight water in performance or racing applications while still reducing rust and deposit formation. It’s formulated to work alongside ethylene- or propylene-glycol antifreezes to maintain corrosion protection when used as directed.

• Meets industry-standard corrosion testing for glycol-based coolants
• Helps prevent scale and rust when used at the recommended dose
• Compatible with newer long-life antifreezes and DEX‑COOL formulations

How much should I add and how do I use it?

Dosage is simple: one 12-ounce bottle treats most passenger cars and light-truck systems holding roughly 3–5 gallons (13–16 liters). Larger cooling systems may require two bottles; very small systems can be dosed by the ounce. Add it to the coolant overflow, radiator, or during a coolant change, then fill to the proper level and run the engine to circulate.

• Standard treatment: one 12 oz bottle per 3–5 gallons of coolant
• Large systems: use two bottles for full coverage
• Small systems: add approximately 1 oz per quart as needed

Is it safe to use with existing antifreeze products?

WaterWetter is formulated to be compatible with conventional ethylene- and propylene-glycol antifreezes, including long-life and DEX‑COOL types. It enhances heat transfer without replacing the freeze/boil protection properties of antifreeze; follow antifreeze manufacturer instructions for mixture concentration.

• Works with most glycol-based antifreezes to improve thermal performance
• Not a replacement for antifreeze—use alongside proper coolant concentrations
• Suitable for use in performance and daily-driven vehicles when dosed correctly

Who is this for: Red Line WaterWetter is aimed at performance drivers, racers, tuners, and vehicle owners in warm climates who want improved cooling efficiency or who run reduced antifreeze concentrations. It’s also useful for anyone performing maintenance who wants better heat transfer and reduced scale or rust formation without changing their existing coolant brand.