Idle Time and other Numbers

[MullenaxM]

Although Idle time is Important , In my opinion there is another number, as a owner, I would be more interested in. Also as a Technician it is one of the data parameters than I look at to help with my diagnosis of trucks with issues with the aftertreatment systems.



I look at this number in my area and have formulated a base line and average for this number.



If I could get Ya'lls help (sorry, remember I'm in Texas) I would like to try something. I think this will help me as well as give you another tool to help with understanding the 6. 7 liter diesel and in my opinion give you data parameter that you can use.



First, Go out to your Truck and get in and turn the key to the Run position (don't start the engine), Next make sure your odometer is reading the mileage and is not on the trip meter. With the odometer reading mileage and the key in the run position, press and hold the trip meter button in, hold it in until the mileage numbers change ( It will take about 10 to 20 seconds for the numbers to change). When the numbers change you can release the button.



On a piece of paper record the number that displays on the odometer,this is the engine run time in hours, then push the trip meter button one more time, the mileage should be displayed. Record the mileage on the piece of paper.



Next, go back in the house and get a calculator. enter the mileage and then divide it by the other number.



When you get done come back here and post the answer. You'll probably end up with a number like : 36. 430834. Just post the whole number and the tenths,(ie: 36. 4).



Some of you may already know what this number means.



Mike

 

[firemansdiesel]

2131 miles w/ 54 hours



39. 4

 

[dlmetzger]

19248 miles and 630 hrs = 30. 6 miles driven/engine on time.

 

[Hoefler]

31133 miles / 864 hrs = 36. 03 mph

 

[HBarlow]

My truck reads 53,734 miles driven with 1,285 hours of engine run time. The average is 41. 8 mph.

 

[MullenaxM]

Correct, This is the average of miles per engine run time. This is a good number to know, it will give you an idea of how efficient your engine/truck is being used. It also is a pretty good barometer of the idle time.



Most of the trucks I see are in the range of 30 to 40 miles per engine hour. With a miles per engine run time of 35 I would expect to see a idle time of about 22 to 25%,with a miles per engine run time of 45 I would expect to see a idle time in the 19 to 20% range.



Also this is a good way to look at fuel mileage since the more miles per engine run time you can get, the better the fuel mileage will be.



Mike

 

[DHuffman]

5,359 miles, 139 hours, 38. 6 mph

 

[firemansdiesel]

So, what is considered too high of a %% w/ idling?

 

[EB]

My truck now has 217,645 miles on it with 4761 engine hours. The miles have nearly stopped now since I no longer haul. The oilfield is dead in my area. I'm now running a grain elevator 7 miles from my house. I might start hauling again if the oilfield picks back up, but with the political situation the way it is, I don't see that happening anytime soon.

 

[gsbrockman]

28,457 miles / 737 hours = 38. 6 avg mph



Greg

 

[Wiredawg]

2,654 miles/59 hrs = 44. 98 mph

 

[HBarlow]

EB's truck @ 217,465 divided by 4,761 calculates out @ 45. 71 mph.

 

[S.Morris]

282000km=175000miles@3600hrs=app. 48mph.

 

[domehead]

8379 / 200 = 41. 895

 

[MullenaxM]

So, what is considered too high of a %% w/ idling?

An idle time of 25% or less is with in the acceptible range,any more than that there is a possibilty of too much carbon deposit build-up in the combustion chamber and on the injector tips.



So if your miles per engine hours are less than approx. 31 there is a chance you may see carbon deposit issues.



Mike

 

[MTapia]

4995/201 =24. 85

 

[CEly]

20239/730=27. 7

Not so good

 

[WillRoach]

31943/874: 36. 5

 

[sabersix]

5285 miles / 112 hours = 47. 19 mph

 

[JohnBower]

21941/703 = 31. 2. I believe this is at the lower desired value for this. What can be done to improve this? Also is the carbon problem the only issue associated with low numbers?

Inquiring minds want to know.