Ted
The pilot formerly known as Twin Engine Ted
- Joined
- Oct 9, 2007
- Messages
- 29,999
- Display Name
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iFlyNothing
I've run a little experiment in my automobile. There are those that said they would never run 5w20 in an engine, and that manufacturers only recommend it so they guarantee the engines last only so long. 5w20 is the manufacture recommended weight for my auto. So, I decided to see if 5w30 made any notable difference it my auto's temperature indication. It did, after reaching normal operating temperature it was a full needle width hotter than with the recommended oil. I immediately drained the 5w30 and refilled with 5w20 and the temp was back to normal.
This is what I would expect. A lot of people don't realize that thinner oil will get better mileage and the engine will run cooler (less work going into pumping the oil). This, of course, requires that the engine be designed for it.
Consumers Report did a scientific study on engine oil change intervals. I think 7500 miles was their winner but I dont recall for sure.
There are so many variables that go into an oil change interval. Are you doing all highway? All city? All towing? All city towing? How big is your sump? What are the clearances like? What temperature does the engine run at? (I'm talking internal, not coolant)
The OEMs that have come up with the oil change light based on an algorithm have it down pretty well. So, I follow the recommended oil type and change the oil when the computer tells me to. I'll usually change it a hair early, but never by much.
How long you go between oil changes in the plane also has variables. For example, I did 50 hour changes in the 310. It didn't burn much oil between changes and looked clean. People I see who fly ROP tend to need to change at 25 hour intervals - the oil gets very dirty much quicker, but I always ran LOP and kept the head temps down. In the 414 I did my first change this weekend (20 hours) but I'm currently running it ROP since the engine monitor went TU and plus it's been sitting a long time, so I figure that it'd be good to do some more regular changes for the time being.