Is there a formula or rule of thumb that equates Idle time hours into mileage?

Trying to gauge timing for oil change

Thx

 

Well, no one here has been able to figure out exactly how these trucks report idle time to the results that we see in a system check.

I thought the manual stated 1 hour of idle should be calculated to 25 miles of driving.
However, I cannot find that tidbit of info.

 

It has to count low RPM in town driving as idle. I have about 25% idle time. That is just BS. There is something in the manual about the right %. Its Probably Ford setting the stage for improper maintenance or something because there is no way someone can be in the normal range unless you run the highways all the time. I don't sit around and idle.

 

Ford considers low speed 25 MPH and under so I wonder if "low speed" is calculated as idle on the computer.
Idle is obviously 0 MPH but how else do these trucks get that much idle time...

 

i am running about 24% idle time

Which if it based on 25 mph or less makes sense

so can I assume that if I take engine on time and divide that by engine idle

so 100 / 25 = .25

Then use that again current mileage between oil change

5000 x .25 = 1250 so this would be approx 6250 "miles" on the existing oil?

Does that make sense?

Is this a reasonable assumption or am i mixing apples and oranges?

 

Well, you could just change the oil when the truck tells you too. I got about 8,000 miles on my last cycle.

 

I could but I plan to change around 5K

I know its OCD but I am comfortable with that

 

Okay a tidbit of info from a field engineer on idle hours. I asked how there fiqured because where I life I see very few small towns and not much idle at all, but my hours dont add up.

He said that anytime the pcm sees the tps throttle position sensor in a idle position. If go up a hill it sees tps but if you are completely off the throttle going down the hill,it is adding idle time. It dont care what rpm engine is. Now this makes sense at least to me. Is he correct? I believe so.

Now this I can believe as I went on a fairly long trip almost all highway but rolling hills so on and off throttle. I could not believe the amount of idle hours it racked up. But. Then had to go on same trip loaded trailer.so it did not see much letting completly off throttle much and didnt show a increase in idke time.

 

Going off this information, stop and go traffic will rack up the idle time to. Even if just rolling without your foot on the gas.

 

Well, the beauty of Internet forums. It has taken three years to finally get someone to figure it out and explain it sensibly. It's hard to confirm the theory here officially via ford but this theory makes complete sense. Many thanks slider.