Originally Posted By: demarpaint
We're getting close Gary. I just forwarded this thread to an old friend who runs a machine shop. I speak with him from time to time. He emailed me back, his reply:
As someone who has torn apart numerous engines with different oil choices and driving patterns I can most certainly tell you that the engines that are way worse are always those that have been excessively idled and/or were in stop-go traffic conditions for most of their operation. I have witness burn't valves, excess carbon, piston scoring, stuck rings, engine sludge, excessive varnish, sticky lifters, plugged up pick-up tubes, you name it I can attribute it to stop & go or short trip driving. Extended drains don't help these engines, get the dirty oil out, it's cheap enough.
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Gary based on engine on time that Cab with 400,000 miles you make reference to really has over 2,000,000 miles worth of wear?
In a nut shell that engine driven 80+ miles is going to be light years ahead of the city driven engine. More frequent oil changes in stop and go is the way to go
Your friend saw engines either neglected or with design flaws. He may be able to tell you the mileage, but I'll venture to say that he hasn't a clue of how much fuel went through them nor the maintenance habits of the drivers.
Our good friend Doug Hillary taught me this lesson ..more or less without even knowing it. I've heard it said or referenced before, but he allowed me to visualize it clearly.
We had a thread where he just blurted out "There is no such thing as magic oil! If it exists, I've never heard of it and have certainly never seen it!!"
He then went on a protracted description of how he ran synthetic lubricants and his competitor, who he also maintained their rigs in his service center ...running side by side...
No significant difference in overhaul rates. Now what he did have was about 1/4-1/5 the downtime since he ran the synthetic.
Now guess what else was about the same in those engine? Yep, fuel economy/usage. Even if 1% was realized and could be leveraged around added costs, it would be adopted.
So, we have 1/5th the maintenance with the same fuel used and the same overhaul rate. Or 5X the maintenance ..same fuel..same overhaul rate.
A water craft engine ran at 1/2 output (not half throttle) maintained at the same level will last twice as long. A water craft engine ran at 1/2 output maintained twice as often won't last four times as long.
I'm saying that one year with SSO or any of the designated Amsoil fluids will maintain the engine over one year with no loss of utility due to lubrication failure or lube aggravated conditions. About the only disclaimer I would make would be if the engine evidenced a characteristic design defect.
For example, I'm sure your machinist friend has seen a ton of 3.0 Mitsubishi's in his career. What was he doing to them? He was reworking the heads for bad valve guides and doing a valve job "while you're there".
I would say that the hardest service per mile would be something like a jeep (or any other vehicle used in this manner) on a farm or summer camp where it only plows snow or does off road golf cart duty and sits for the rest of the year. Even those tend to take decades to require an overhaul (admittedly your standards tend to be different for requiring one).
