OIL LIFE MONITOR
OLM systems monitor crankcase temperature, combustion chamber events (the
work the engine does), and the time since the last oil change in order to come up
with an approximate percentage of usable life left in the engine oil. Computer
algorithm specifics for these systems vary from carmaker to carmaker. However,
overall they are accurate in determining the amount of serviceable life left in the
engine oil. The key is to make sure you use the recommended oil the carmaker
specifies and to reset the monitor every time you have an oil change. Otherwise
the system will be thrown off because it’s not intuitive.