A more truthful answer is: Bypass filtration can lead to a cleaner sump than new oil, how much this can affect engine longevity, no one knows. Common sense says that an engine run constantly on clinically clean oil should outlast an engine that ISN'T run that way, but there aren't any real world studies that prove so; or disprove so. And I have no opinion on your diesel lawn mower, but Mr. Newton is addressing a much larger issue and I feel compelled to respond.
Caterpillar says that 75% of component failures are the result of surface degradation caused by (oil) contamination. Unfiltered new oil is one of the worst sources of particulate contamination, and is typically not suitable for engines, transmissions or hydraulic systems...Caterpillar recommends cleaning new oil to a minimum of ISO 16/13 before adding:
https://www.hyprofiltration.com/clientuploads/directory/CaseStudies/PDFs/CAT 5 Star.pdf (p2)
Mr. Newton is basing his answer on his own OPINION; and there are well-educated, researched, qualified, and informed opinions that disagree with Mr. Newton. For example:
Machine Life Extension Table
During the training, you’ll learn how to achieve up to 10X machine life extension for gearboxes, bearings, diesel engines, turbo machinery, and hydraulic system components. You’ll use this reference table to help plan and manage your machine life extension efforts.
http://65.38.6.88/Read/26649/Oil-analysis-Noria-training
http://www.upstreampumping.com/article/p...nitoring-system
https://www.google.com/search?q=life+ext...KHWGzBpgQsAQIKQ
"BP filters extend OIL life, not equipment life." This statement is Mr. Newton's opinion, and can be contrasted with the fact that Noria Corp. has built a world-wide industry extending equipment life through fine filtration (sometimes bypass) and good maintenance practices to avoid particulate contamination.
Here is an opposing perspective from this site, no less: "There is a common feeling by many BITOGers (that have posted on this forum) that the primary benefit of bypass filtration is extended OCIs. Most people don't keep their vehicle long enough to realize the extended engine life that bypass filtration offers. But I disagree: In my opinion, the primary benefit is engine longevity, and extended OCIs is an added benefit."
http://www.bobistheoilguy.com/forums/ubb...cle#Post3010405
There is MUCH that I agree with dnewton3 on...I agree that bypass filtration and synthetic oil with 5-7-10-12-15K oil changes is a total waste of money. I agree that short-tripping with bypass filtration is a waste of money. I agree that there is a point of diminishing returns to the point that finer filtration is pointless...Although I might DISagree as to the ISO code of what that point is...I agree that bypass filtration is NOT a solution for poor air filtration, leaking gaskets, coolant in the oil, etc...Those are separate maintenance issues that must be addressed; and ANY benefit of bypass filtration ASSUMES an engine to be in sound mechanical condition.
Let's do an analogy; as Mr. Newton is so fond of: Let's say that you just bought a new vehicle; and there are many sources that compare particulate contamination in motor oil to sandpaper (abrasive) in your engine. Ok, I'm going to take sandpaper to the paint finish on your new vehicle. What grit paper do you want me to use? The finer, the better? Say 3000 grit is OK, but you'd rather I didn't do it at all? Then why use oil in your engine that has grit in it?
Indulge me to quote Jim Allen:
"As far as many of us can tell, and we have asked professionals in the field, no real-world study has been done that shows an improvement to X% filtration from a lower efficiency yields &% less wear. The fact is, nobody really knows how much less wear results from a 15um primary filter vs a 30 um in an engine used the way most people do and with normal contamination inputs. It stands to reason there are wear improvements with better filtration, but whether they are significant, or significant enough to warrant the extra expense necessary to achieve them is the big question. In other words, Return On Investment (ROI)."
(This is in agreement with Mr. Newton, it just points out the lack of real world studies to substantiate the opinion, which I believe should be stated as such, not presented without qualifiers as Mr. Newton does.)
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3016344/2
Furthermore, and in contrast to Mr. Newton's references of "normal" everyday oil, filters, oil changes and maintenance lasting 4 engines a million miles and being celebrated with free hot dogs and soda at the servicing dealer (why not, he's given them a LOT of business!)
In the real world of bypass filtration being effectively used, here is a trucking company that has taken a fleet of ONE HUNDRED TRUCKS a million miles EACH, without so much as an oil change; so here's a discussion about reality:
http://www.marketwired.com/press-release...ange-793914.htm
And there are more like this:
http://www.gulfcoastfilters.com/Testimonials.htm
I would say that in the world of bypass filtration, million mile engines do not need to be celebrated, they are routine.
Why not approach any of these men and ask them to disconnect their bypass and see how long their engines last? I'll tell you their responses: Get your wallet out and pay for my engine. Or else their responses will be (censored on this site).
I'm not trying to be contentious or disrespectful with Mr. Newton. He is a statistical engineer, and I believe a site administrator here on BITOG. Mr. Newton authored this and holds copyright:
http://www.bobistheoilguy.com/used-oil-analysis-how-to-decide-what-is-normal/
However, I disagree with his hypothesis that clinically clean oil does NOT aid equipment longevity; and I will leave it to others, far more educated than I, to define "clinically clean oil." I would venture to say that an ISO code beginning with a 16 is probably a good starting point. I simply state this because of my extensive reading OUTSIDE this site.
Finally, if bypass filtration were to become routinely used here in the good ole USA and did NOTHING but reduce public oil consumption by 85-90% (as many bypass manufacturers claim), what would be the harm to the economy or environment? Mr. Newton and I would probably agree that even here on BITOG, it makes my stomach turn to see how many posters run synthetic oil and still change it at 7-10K miles.
Yes, I agree with Dave Newton that any product can be over or under utilized; and synthetic oil changes at 10K are grossly underutilized.
So, how much longer will an engine last with clinically clean oil? I would say indefinitely, along with other sound maintenance practices, but I can't prove anything, and neither can Mr. Newton; without somebody spending a LOT of time/money/research.
The full truth is no one knows, including dnewton. I just wish he'd admit it.