Sawyer Rob
Addicted to ArboristSite
The ones I've seen were based on how much fuel is burned.The oil life monitoring is time based not mileage based Jeff. At least on Fords. When I got my new 2009 it sat off and on for a few months because I was using my van to haul produce. Only had about 1,000 miles on it and got the change oil now message. Asked my Ford mechanic and he said just reset it. AND Synthetic oil for the win!!
Towing burns more fuel, so the oil needs changed more often, trips use less fuel so the monitor goes down slower.
That's how it works on my Silverado, and it's the proper way for it to work. I'm down to 10% now, so I'll be changing the oil soon.
SR