Valvoline Zerex G48 Antifreeze/Coolant Concentrate 1 gal — HOAT corrosion protection & extended life

Valvoline Zerex G48 Concentrate is a 1-gallon, hybrid organic acid technology (HOAT) engine coolant concentrate formulated to protect aluminum and other cooling-system metals while extending service intervals.

This one-gallon concentrate blends advanced organic acid technology with an ethylene glycol base to deliver corrosion protection, freeze and boil control when mixed to the proper ratio. Developed in collaboration with industry formulators, the Zerex G48 formula is engineered for modern engines that use aluminum components and require a long-life coolant solution. Use it as directed to prepare a ready-to-use coolant that meets manufacturer specifications for many passenger cars and light trucks.

How do I mix Valvoline Zerex G48 Concentrate for my vehicle?

Mixing the concentrate correctly is essential for proper freeze and boil protection and to achieve the inhibitor levels expected from the formulation. Typical practice is to dilute with distilled water to the vehicle maker’s recommended concentration, often 50/50 for year-round protection, though some climates call for higher concentrate ratios.

• Standard dilution: 1 part concentrate to 1 part distilled water for general use.
• For extreme cold: increase concentrate ratio per manufacturer guidance to lower freeze point.
• Always consult vehicle owner’s manual for approved coolant type and concentration.

What metals and components does this coolant protect?

Zerex G48 uses a hybrid carboxylate inhibitor package designed to protect aluminum, cast iron, solder, brass, and other common cooling-system metals used in modern engines. The organic acid technology helps maintain a stable inhibitor level over extended service intervals, reducing localized corrosion risk in mixed-metal systems.

• Protects aluminum components commonly found in cylinder heads and radiators.
• Compatible with brass, copper, and cast-iron water pumps and blocks.
• Formulated to resist buildup that can impair heat transfer and flow.

Is this coolant compatible with other antifreeze types?

As a hybrid organic acid technology (HOAT) concentrate, Zerex G48 should not be mixed with inorganic additive technology (IAT) coolants or some fully organic acid technology (OAT) formulas without a complete system flush. Mixing different inhibitor chemistries can reduce corrosion protection and shorten service life.

• Do a full coolant system flush before switching to G48 from dissimilar chemistries.
• When topping off, use the same product family and inhibitor type to maintain balance.
• Refer to vehicle manufacturer recommendations for approved coolant types.

How long does the protection last once mixed and installed?

Zerex G48’s hybrid carboxylate formulation is designed for extended service intervals compared with traditional IAT coolants, but actual longevity depends on vehicle application, maintenance, and operating conditions. Regular coolant testing and periodic inspections will confirm inhibitor condition and overall system health.

• Expected extended service life when used as directed and combined with proper maintenance.
• Monitor coolant condition and follow vehicle maker or service-provider interval guidance.
• Replace if contamination, pH shifts, or degraded inhibitor levels are detected.

Who is this for: Valvoline Zerex G48 Concentrate 1 gal is aimed at professional technicians, do-it-yourself mechanics, and fleet managers who need a long-life coolant compatible with modern aluminum-intensive engines. It’s appropriate for owners switching to a HOAT-style coolant or maintaining vehicles that specify Zerex G48 or equivalent hybrid OAT formulations. Always verify compatibility with your vehicle manufacturer before use and follow mixing and service guidelines for best results.