Delo Extended Life Coolant/Antifreeze - Nitrite Free (DELO ELC-NF) is for on- and off-road equipment that require a nitrite-free OAT formulation. It offers a service life of 600,000 miles; 12,000 hours; or six years with no chemical extender needed, the company says. It also offers corrosion protection and lower electrical conductivity; protection against pitting, corrosion and erosion; and improved water pump life.