Engine Hours instead of Mileage
- Thread starter Nyati
- Start date
What's the problem with idling? It's probably the lowest stress engine running situation there is.
Everything, more fuel dilution, overheating engines. Idle engine makes zero mpg and zero horsepower.
I believe that some makes use run time into account. I know that GM has counted RPMs, average oil and water temps, time elapsed, average load and similar factors to calculate the OLM percent. The OLM algorithms can be fairly sophisticated.
It would make sense. Running 100 hours on the interstate is far more miles and far less stress than 100 hours in city traffic. Problem is - how many hours?
Its the same as mileage - you need to use some common sense in the mix.
Its the same as mileage - you need to use some common sense in the mix.
Where do people come up with this stuff? This isn't 1970 with carburetors and mechanical fans. Idling engines put out minimal heat compared to one under load. If your car overheats idling it has a cooling system problem. Police cars idle 8 or more hours a day sometimes.
Obviously but irrelevant to OP's topic.
With some DI engines that is a problem. There are DI engines that fuel load the oil like or worse than a carbed motor. Idling and short trips loads up the oil and drops the viscosity , until its driven hot enough to boil it off.
OLM's take in to account idling.They are more sophisticated that some comments on these oil threads.
Idling does result in some amount of cylinder washdown, fuel washing oil off cylinder walls (bigger issue on a diesel). The newer intelligent OLMs factor that in, though. I’m not sure how much I trust GDI engine OLMs-they seem to ruin oil pretty quickly with short trips & idling.
I heard that combustion events and injector duty cycle were the main components, as the fuel becoming contaminated is the largest contributor.
Mine also chops approximately 10% per month due to a yearly change interval independent of any engine operation.
Low RPM also hurts camshafts as the oil wedge does not build up as thick on the lobes. It may not be a big hurt but it definitely results in more wear than when the RPM is some higher.
Ali
Ali
Why MOFT matters first and foremost thin isn't in.
Exactly!
Patman
Staff member
Nope. The lowest stress for an engine is cruising on a flat highway at a steady pace. You don’t really get proper oil flow at idle.
When I am driving above 30 mph even with a light beating I stay at around 178-187F in the summer in Minnesota. I idle and then I am up to 215-220F. The factory setting to start the radiator fan on low with no air conditioning is 215F. With air on around 195F. In summer I get to 215-220F in a hurry in stop and go traffic. Just idling in the driveway pretty fast after the initial longer period it take to full heat soak a cold engine. I have 50,000 on the car and the motor doesn’t like 215F as I feel it getting tighter. Probably a Hyundai thing, why they gall up piston skirts. I luckly have one of their “ accidental “ good model engines. It still is living after a hard LSPI hit when it was new and higher boost and thrashed daily. Oh, and the fan on low doesn’t bring it back down to 178-185F. It stays high.
I probably idle enough to make up for those in this thread who try to avoid it. I change between 10-15% on the OLM on my F250 and its usually around 200-300 hours if memory serves. I can check notes if needed. All of my stuff idles a lot. I spend most of my day working between my vehicles and I like my AC and heat.
I ran 3 commercial gas vehicles in NYC idle time traffic 7 hours a day was a issue not miles. No hour meters so just changed the oil every 8 weeks regardless of miles put on.
Similar threads
