Idle Hours Meter - Ram, Ford, GM?

[Itchytoe]

Originally Posted by BubbaChris

I'd really been hoping to buy a 3/4 gasser as a next truck rather than jumping all the way to a 1-ton diesel. But the more I look at key facts, the more I'm biased towards buying big with no regrets:

• We live at 2,300' and camp all summer at 7,000' or higher

• The fiver we currently like the most has a GVWR of 15,000

That's really all I need to know right there. Don't get that 3/4 ton gasser. You're in mountains and will be pulling over 20,000 pounds combined weight. You will be so much happier with the bigger diesel. Ride difference is negligible at most between a 3/4 and 1 ton.


As far as idle hours go, try to stick with 20% idle hours or less. If you find one in good shape with 22%, don't be scared of it though. Lower is better, because it means the truck has been on the road doing what it's supposed to do. A truck with 50% idle hours has been sitting in the drive through or stuck in traffic jams all its life. That's really hard on a diesel engine. Diesels need to burn hot. It keeps emissions equipment cleaner and running properly, and it helps keep the oil cleaner and less fuel diluted. Fuel dilution is a killer. Diesel doesn't lubricate like motor oil, so when your oil gets diluted with diesel, the resulting mixture doesn't keep your engine safe.

[tuffr2]

I just checked my 2017 gas F-250. Engine hours 248 idle 48. I am in Florida so a few times I run the engine for the A/C.

[jimcumminsw]

Originally Posted by Old-Biscuit

Idle is very inefficient ...fuel can wash cylinder walls which can increase wear.

That is why Ram trucks has an High Idle feature on their diesel trucks. I use this all of the time when I idle my truck. The truck will idle between 1100 and 1600 RPM's so, cylinder wash does not happen.

The engine hours have been on Ram/Dodge diesel trucks since 2008 and earlier if I remember correctly. I know my truck has this feature (engine hour meter) on it and the truck is a 2008 model.

[powerboatr]

ford has had HIGH idle since day one with the 6.9, then 7.3 then the 7.3 with brains and the 6.0 and up


my 6.0 had two high idle settings, one for pto and one with out, one would lock the tq converter the other let the tranny free float.



dodge ram and gm have the same, its just a matter of switches.



my bus tells me %of idle in engine hours,



i would expect a fleet truck to have high idle times.

[tuffr2]

What makes more sense to you guys? 25 miles per hour idle time or 33 miles? I personally think 25 miles makes a little more sense since the engine is running at the lowest RPM it can and no strain in the engine.

As a kid I disconnected the gas line from the gas tank of a V8 powered car and ran the 1968 car at idle until it shut off. I was fixing a rusted gas line. Anyway the car ran for probably 5 to 8 minutes. I was surprised at how long it ran.

In modern vehicles I am thinking idle time and a corralation to hours has to be going down as I keep hearing and believe tolerances in engines is better. Actually now 25 miles per hour of idle time seems a bit high.

I walked by two big tri-axle dump trucks a few days ago. Both were at high idle for at least a hour while I ate lunch close by. High idle explains to me why a diesel engine is so loud when at idle...it is because of the high idle it is doing.

My 2012 F-450 seemed to always idle at 900 to 1,100 RPM. Now I know we why.

[Itchytoe]

Neither of those figures make any sense to me. The issues you get with idling aren't the same as driving any number of miles. It's a different mechanism. It's like asking how many rifle shots dunking your barrel in salt water is equal to per hour it's under water. Or how many heat cycles is a drop of water in your brake fluid equal to?



You don't just run into the same problems faster with idling. You run into different problems entirely. Idling above 1100 RPM is a decent way to reduce most of those problems, but an idling engine isn't under load, so it's not perfect.

[tuffr2]

Itchytoe - what number of miles do think is fair to assign to 1 hour of idle time?

I keep trying to remember 1 hour of idle time is a long time with all the same moving engine parts as when the truck is moving. That being the case I can believe 15 miles and even 20 miles per 1 hour of idle time.

But if commercial fleets use 33 or 25 miles equal 1 hr. of idle time they should know.

[Itchytoe]

Originally Posted by tuffr2

Itchytoe - what number of miles do think is fair to assign to 1 hour of idle time?

I was trying to point out that an hour of idle time doesn't translate to any number of miles because of the differences in how the engine physically operates at idle vs at 1500 RPM+. It's the basic concept of idle hours converting into miles that doesn't make sense.

If you're dead set on figuring a number, do the math for each vehicle. It's not really a complex calculation. Take the number miles total on the vehicle (current odometer) and divide that by the number of non-idle hours (total hours - idle hours) to figure out an average miles per hour for the time the vehicle was not at an idle. Then use that average miles per hour and multiply it by the number of idle hours and add that to the total miles to figure out the "true" miles worth of wear on the engine if there were no idle hours at all. If you just want an average, go with 30.

[BubbaChris]

Revisiting this thread

We created a situation where buying new was the better option for us, so I wanted to feed my results back to the forums in case anyone else searches on the subject. Living in the desert and traveling with our dogs, leaving the truck running while we setup or break camp is necessary. So you could have the potential to reach the same mileage with fewer idling hours.

My stats after living with the truck for a few months:
6003.3 miles on the odometer
200 Engine hours
48 Engine Idle hours
Truck had 40 miles on it when we picked it up, so my detailed tracking on mileage and fuel usage starts from there.
5,960 miles
538 gallons of diesel
11 MPG overall
10 gallons of DEF (roughly)
2,905 miles of towing
29 nights of camping
Only 7 complete tanks of fuel without any towing - 14-16 MPG on those tanks
Towing MPG has not dropped below 8 MPG, mostly mid 9's
Ford's trip computer is always optimistic on MPG, so all above numbers are calculated.
My commute is 11 miles each way, mostly 40 MPH roads
2,900 lbs pin weight
14,000 lbs fiver loaded for camping
Multiple trips towing to over 7,000 ft elevation

Best regards,
Chris

[tuffr2]

BubbaChris - did you find that your truck would shut off if idled for extented times like 30 minutes?

My truck shut off after a certain time of idle. Unfortunately I was not paying attention to the exact time. I pulled over to make a phone call and was letting the truck idle to keep the A/C running to stay cool on a hot day. It seemed to shut off after 20 or 30 minutes.

I mention this because you have dogs. On a hot day just be aware that the truck will not run indefinitely.

My truck is a 2017 F-250 6.2 gas.

[Jshopes81]

My 17 work dodge has like 500hrs drive time at 110,000 miles and around 2500 idle hrs. I think the guy that had it before me let it run for a few weeks straight. You CANNOT let the new trucks sit and idle. Period. The dpf will clog.

I was always told 35mph x hrs for the true wear on an engine, so 33 sounds pretty reasonable.

The 6.4 experiences oil dillution because of the way it regens. It has an added injector event on cyls 7&8 on the exhaust stroke to force raw diesel into the dpf and burn it out. This can cause excessive heat to be run through the turbos and wash the cylinder walls of oil which causes excessive wear to the rings, pistons, turbo, and bearings in the rest of the motor as the fuel gets pulled down into the crank case. Do NOT mess with a 6.4.

I wouldnt buy a vehicle with a ton of idle hours on it, wear is wear.

[jimcumminsw]

You 'al realize that with an engine being at idle, this is only the engine that is being used. What I mean is the rest of the truck is not being exercised such as transmission, transfer case if it is a 4X4, wheels, brakes, u-joints and so, forth. So, trying to compare idle hours to miles driven is not a very accurate measurement.

Construction equipment with diesel engines, can idle on an off all day long with no adverse effects on the engine or tractor. Other than having a higher fuel bill at the end of the day do to idling.

[jimcumminsw]

Originally Posted by Jshopes81

My 17 work dodge has like 500hrs drive time at 110,000 miles and around 2500 idle hrs. I think the guy that had it before me let it run for a few weeks straight. You CANNOT let the new trucks sit and idle. Period. The dpf will clog.

I was always told 35mph x hrs for the true wear on an engine, so 33 sounds pretty reasonable.

The 6.4 experiences oil dillution because of the way it regens. It has an added injector event on cyls 7&8 on the exhaust stroke to force raw diesel into the dpf and burn it out. This can cause excessive heat to be run through the turbos and wash the cylinder walls of oil which causes excessive wear to the rings, pistons, turbo, and bearings in the rest of the motor as the fuel gets pulled down into the crank case. Do NOT mess with a 6.4.

I wouldnt buy a vehicle with a ton of idle hours on it, wear is wear.

Read post 17 in this thread!

[Jshopes81]

Originally Posted by jimcumminsw

Read post 17 in this thread!

I read it the first time through and high idle or not, they clog. It happens in everything from 6.7 to ism15.