Actually a couple of questions. I've had one oil change in my F250 6.7. Getting close to the second one. So, my question is, what is the computer using to decide when to tell you that you should change the oil? And, if you changed to a synthetic oil, could you go longer between changes? And, if so, would the truck's sensors be able to tell the difference in the type of oil being used?

 

No it will not know the difference in oil type.
Generally it goes by trip distances, Miles, hours, how many times the truck was started and so on. Some guys go by it some don't.

 

I have a 2007 6.0 PSD, but I use Royal Purple 15W40 diesel. I change the oil & filter, go 5,000 miles, change the filter and go 5000 miles more. Then I change the oil and filter again. I know the distributor in my area, and he said that with Royal Purple, I could got 7500 miles and then do the filter, and then go another 7500 miles, and change everything again. Been doing it for 3 years, working fine.

 

It is strictly an odometer counter. That's it. Straight from Ford on that one.

 

Well, that's not correct that it is an odometer counter. The 2015 and later 6.7 diesels have an intelligent oil life monitor (IOLM) system that determines when you should change your engine oil based on how your vehicle is used. By considering several important factors in its calculations, the IOLM helps ensure that your engine can perform at its best while also helping you avoid unnecessary oil changes. Straight from Ford on that one.

When to expect the OIL CHANGE REQUIRED message to show (This is from Ford regarding the IOLM system)

Vehicle use

Interval

Normal
•Normal commuting with highway driving
•No loading or towing, or moderate loads and towing
•Flat to moderately hilly roads
•No extended idling
7,500-10,000 miles (12,000-16,000 km)

Severe
•Extended hot or cold operation
•Moderate to heavy loads and towing
•Mountainous or off-road conditions
•Extended idling
5,000-7,499 miles (8,000-11,999 km)

Extreme
•Extreme hot or cold operation
•Maximum loads and towing
3,000-4,999 miles (4,800-7,999 km)