Phillips 66® Guardol OAT HD Coolant/Antifreeze is an Organic Acid Technology (OAT) that is intended for use and compatible with any OAT extended life heavy duty coolant/antifreeze in any diesel commercial vehicle engine or stationary engine with aluminum and other various engine metals. The advanced formulation is based on a concentrated blend of long-lasting inhibitors designed to provide up to 600,000 miles/12,000 hours* of protection against temperature extremes, corrosion, scale, rust and premature water pump failure. Guardol OAT HD Coolant/Antifreeze is available in both concentrate and prediluted 50/50 formulas.
*TOP OFF: Will maintain extended life protection when added to any OAT extended life antifreeze/coolant.
FLUSH AND FILL: Receive protection for up to 600,000 miles or 12,000 hours with a complete flush and fill using Guardol OAT HD Coolant/Antifreeze.