The importance of recommended AFC change intervals

In the world of heavy duty antifreeze/coolant (AFC), the great white whale has been the number one million, as in, "One million miles of engine operation between coolant changes." This claim is seductive for any number of reasons: one million is an impressive, eye-catching number; it dovetails neatly with the never-ending search to identify the "next big thing;" and, from a more practical point of view, it offers to the heavyduty dri ver or fleet operator the promise of reduced vehicle maintenance and downtime, which, in turn, could lead to increased operating profits.