Idling

Joined
Feb 28, 2003
Messages
11,977
Location
Cajun Country, La.
Is there a formula for trying to figure out how many miles idling a vehicle will put on an OCI? Example, say that I let my 4.2 V6 idle a total of 12 hours in a 5K mile OCI, how many additional miles must I add?
Thank You.
 
12 hours over an OCI isn't likely enough to make much of a difference, in my opinion - I'd stick to the OCI you planned.
What you could do, if you wanted to do some math, is assume rpms consistent with, say, 20 mph at idle, and multiply 20 mph * 12 hours to get a rough estimate of 240 additional miles driven (again, not anything too likely to make a difference).
 
I'm sure you could probably go longer than 5k anyways, the amount of idling time during the OCI is probably pretty insignificant over the amount of extra fudge room you have running a 5k OCI anyways..
 
Is there a formula for trying to figure out how many miles idling a vehicle will put on an OCI? Example, say that I let my 4.2 V6 idle a total of 12 hours in a 5K mile OCI, how many additional miles must I add?
Thank You.
Easiest approximation would be to figure out fuel burn at idle (in gallons per hour). Say it burns 0.5 gal/hour, so in 12 hours it'd burn 6 gallons.

And what is your average fuel economy? Say it's 20 MPG. So 6 gallons of gas would be equivalent to about 120 miles, so you would add 120 additional miles to your OCI.

I'm sure it's more complicated than this, but here is your simple answer.
 
"1 hour of engine idle time is equivalent to 25 miles/40 km according to Ford." Popped up when I searched, not sure of source though.
You would have to idle quite a bit to add up to many equivalent miles.
 
Something to consider with idling, it probably is more considered "extreme driving". Little to no airflow, constant non varying engine speed.
 
Easiest approximation would be to figure out fuel burn at idle (in gallons per hour). Say it burns 0.5 gal/hour, so in 12 hours it'd burn 6 gallons.

And what is your average fuel economy? Say it's 20 MPG. So 6 gallons of gas would be equivalent to about 120 miles, so you would add 120 additional miles to your OCI.

I'm sure it's more complicated than this, but here is your simple answer.

Thats probably a good basis, though time at load/temperature will probably be more degrading, idle will be more fouling.

Quite a waste to idle for 12 hours.
 
A lot of people idle for a long time everyday in traffic jams. If you are in this situation commuting to work and back then take it under consideration when determining oil change intervals. As for converting it to miles, who knows?
 
Typical figures floating around out there are between 25 and 33 miles per hour of idling.
That is what I have seen too. but usually you dont count hours idling unless its a large part of the engines usage..
ie trucks that run 24hours a day for security in parking lots etc.
 
Agree with that - in our fleet we have trucks that go like normal, and we have trucks that drive a 1/2 hour and then idle for 7 hours at a job site, then a 1/2 hour back. Those do have idle hours accounted for in determining PM times...
 
My truck has 15,060 miles at its last oil change and has 669 total hours and 168 idle hours. I use remote start quite a bit if that figures in the equation, I’m assuming it does.
 
The difference in driving and idling among different users and areas is very broad in the US.
exessive idling is considered severe use but excessive is Never quantifies. Cars come with remote starts to warm or cool the cabin for the people, but no adjustment is suggested for the OCI.

Much like towing for 250 miles I dont think a few moderate idles like in. A drive through bank,pharmacy or food joint make much difference.
If you drive mostly on dirt roads, most engine hours are idling(such as police or taxi service) or most hours are towing a trailer (you do lawn care or are a fishing guide who pulls The boat to the ramp every morning, then I would say that is severe.

If you do a little of the above but it is not significant why Would you account for that?
If the factory regular OCI is well proven to be a reliable OCI to follow then The most conservative person such as me would run 75% of the regular OCI if some elements of driving are severe. So I occasionally idle in a drive through or let he truck idle for 5-10 minutes to keep my wife and dogs cool when I run in sOME where in the summer. Or pull a trailer Or drive a little off-road, It’s a very small percentage of the use in reality. And knocking off 25% is probably conservative. I may do some lab on the next dump.
 
I put hour meter in my Caravan since last oil change which I am up to 100 hours at 1500 miles. I was running sever duty of 4k as that is what is in manual. I am still trying to decide on 200 hours, 4k, 5k or OLM oci.
 
Remote start makes it even more severe as you're idling a cold engine, and it takes longer for it to warm up this way.

Yeah I understand that and am waiting on the results of my UOA to see what the oil looks like at 5,000 miles. I am not sure the hour meter is adding time when remote starting but need to do some more testing.
 
Back
Top