A method generates a useful life indication of a lubricating fluid in an engine. Initially, a quantity of use of an engine and a time of use of the engine are measured. A useful life indication of a lubricating fluid in the engine is generated based upon a first relationship between the quantity of use of an engine and the time of use of the engine when an operating characteristic is at or below a predetermined amount, such as the average speed of a vehicle containing the engine. The useful life indication of the lubricating fluid in the engine is generated based upon a second relationship between the quantity of use of an engine and the time of use of the engine when the operating characteristic is above the predetermined amount.