Knowing your inputs is a great way to predict what might happen. But results are the way to know what actually happened.
Knowing that PAO oils will survive the heat a bit better than a dino oil is a fairly well accepted concept; I agree with it. But I would suggest that actually running an HDEO and seeing UOAs will show what is actually going to happen, rather than what "might" happen. VOAs and base stocks are a great starting point, but UOAs provide an understanding of what did happen, not what might happen.
Dino HDEOs probably don't run any hotter in a TC96 than they do in today's turbo-diesel applications. After all, the turbo is driven by exhaust gasses, and EGTs can often get up to 1300 degF for short hard pulls uphill. How is that any differnet than the Harley engine? Heat exposure is heat exposure.
There are two risks regarding heat. One is instantaneous exposure (immediate coking, etc), and one it long term exposure (oxidation/evaporation). You really can't argue that a TC96 has any more potential to coke the oil than does a turbocharger on a diesel engine. I would suspet the temp at the head/upper cylinder of the TC96 isn't any hotter than the heat at the turbo under a load. So in my mind, coking isn't an issue, as dino fluids handle this quite well. So, what about oxidation/evaporation? Well dino HDEOs handle this quite well, too. In fact, people often freak out when their engine "uses oil" by the process of evaporation. So what?!?! Check your oil level once in a while, and top off the fluid! You just replenished your additive package! Big deal. Small amounts of oxidation/evaporation are normal, and don't effect engine life.
My point is that a dino HDEO will perform quite well in the TC96, if you give it a chance. Will it do as well as a top-dollar PAO? Maybe not. But at 5k mile OCIs, and at half the price (or less!) than the expensive PAO-motorcycle-specific oils, the HDEO dinos certainly are worth a look!
Further, let's consider the useage factor of a Harley. It's likely not a daily transport; it's a joy ride. I know; I ride too. Did you know that the average annual mileage of the industry for all on-road bikes is less than 2k miles a year! Sure, there are some of us that go much farther. I ride about 10k miles a year. Some ride more than I do. But let's run some math here. Say you are a hard core rider, and do 15K miles a year. It would take 10 years just to get 150k miles on your bike. And the build quality of today's bikes (all brands) has improved just as much as today's cars and trucks. I suspect that bikes are discarded LONG, LONG before they are "used up". So, what's the likely hood that a Harley is going to experience such high mileage in the first place?
Harley riders, in particular, often want to baby their "baby". They will buy the "best that money can buy" regarding oil, filters, storage tarps, cleaning wipes, gloves, leathers, blah blah blah. Hey - that's great; this is a free-market society after all. But don't try to convince me that $8/qt PAO is NECESSARY to make the Harly run. If you WANT to spend that, go right ahead. But considering the reality that most Harleys odometers will NEVER see 50k miles, PAOs are likely overkill for nearly all applications.
I'm not saying that a dino HDEO would perform "better" than a PAO high dollar oil. In fact, I'll admit that PAOs are likely to do "better". But, I am saying that at 5k mile OCIs, you won't get anywhere near a proportionate amount of "protection" for your money. If you spent $8/qt for PAO-motorcycle specific oil, would you get 4 times the "protection" over $2/qt dino HDEO? Would your UOA show 4x less wear metals, 4x less soot, 4x less insolubles using PAO vs. HDEO? I think not! (BTW - some would challenge the ratio of 4:1 but here's where I came up with that. Dino HDEOs are common, and can still be found on sale if you're savy. Delvac 1300 was on sale with rebate for $7/gallon just last fall. Try and find PAO-motorcycle-specific "on sale" anywhere! It's about $8/qrt no matter what brand or store you see it at. The marketing/sales folks know that people who "want" MC-PAO oil will pay for it; they are a captive audience!).
Here's a thought. Run a few UOAs each way and see for yourself. I have my opinion; others have theirs. Why not remove all doubt, and see for youself. Let the UOAs be your guide, not rhetoric.
