from Ford:
What the IOLM measures to determine when an oil change is needed
Several key factors that affect oil life include:
Driving habits (such as towing and workload)
Hours in operation and at idle
Oil and coolant temperature
Engine speed and torque
Diesel particulate filter (DPF) cleaning cycles
How the IOLM works
The IOLM does not use oil quality sensors – it is entirely software-based and uses actual engine operating conditions to calculate the oil change interval by using an algorithm. This means the system must be reset after an oil change. Not doing so will result in a premature OIL CHANGE REQUIRED message.
The frequency of oil changes
Depending on driving conditions, oil change intervals are approximately:
Up to 10,000 miles - Normal commuting with highway driving
5,000 – 7,500 miles - Trailer tow/high-load driving
3,000 – 5,000 miles - Short trip usage, extreme cold or hot temperature
NOTE: Actual mileage will depend on your specific driving conditions.
Under normal conditions, you will get an OIL CHANGE REQUIRED message at up to 1 year, or 10,000 miles from the previous oil change.
What the IOLM tells you
You’ll find a display in your instrument cluster’s message center that will notify you of oil change intervals by displaying ENGINE OIL CHANGE SOON or OIL CHANGE REQUIRED. The system will also indicate when fuel filters need maintenance, or if fuel pressure is low.*
*Refer to owner’s guide for specific applications.
Synthetic oil and the IOLM
Ford engines have been tested using Motorcraft® Synthetic Blended Oils. If you do use synthetic oil, it needs to meet the Ford specifications for motor oil and the specific oil weight as indicated in the owner’s guide. Ford still recommends using the oil change service intervals as indicated by the IOLM.