KeithInSpace
Veteran Member
Not to nit-pick, but at the beginning, you say that the idea of "Safety Factor" doesn't apply to the discussion, but your later example is the very DEFINITION of Safety Factor.
Folks have been "balancing" small-block Chevy engines since the stone ages. Making no other modifications, a multi-piston engine can rotate safely at a much higher RPM than a "stock" engine. Chevy will redline their engines to 5,500 RPM, for example, BECAUSE they don't go through the effort of picking pistons "from the same bin". That exact same engine that is professionally balanced can safely spin to 6,500 RPM all day long with no other modifications. Of course, beyond that you start getting into valve float and a myriad of other issues that require REAL work on the engine, but my point is this: The factory redline placed on engines is based on 99.99% of the engines built from "multi-bin parts-grabbers" being able to withstand that RPM. Not by the actual "no Safety Factor" capabilities of the engine. The alternative would be a redline specific to the engine of each and every vehicle produced, based on the inherent imbalance of each and every engine. Impossible.
Back to the OP's question: The original question was whether the UDT AND filter, untouched, could withstand another 100 hours of operation. That's 100% longer than the factory recommends.
My personal response, related to Safety Factor: If they built a 50% Safety Factor (believeable) into physical characteristics of the fluid and recommend changing it at 100 hours, my feeble mind would translate that to a REAL duration of 150 hours with absolutely no problems. To DOUBLE the manufacturer's recommendations (foregoing a 200 hour change and making it last to 300 hours, for example), I'd need to rely on a 100% safety factor on the designer's/manufacturer's intent...pretty tough sell in my book.
Yet another example: I run synthetic in my 2005 Expedition. I've done so since 10,000 miles. I also purchase the expensive $12 oil filters. Ford recommends changing the oil every 5,000 miles. I generally change it after 5,500 to 6,500 depending on my mood. I AM relying on "Safety Factor" in my decision to extend service intervals, but I'm also OFFSETTING that decision by using a far superior oil than the factory installed.
Use a "far superior" (far, far, far, far, far superior in this case) UDT and Filter, and perhaps you could justify doubling the service interval. Without that change, I can't see going beyond 125% of the manufacturer's recommendations. In this case, 125 hours. But not 200 hours.
