alancoles
Dress for fall & avoid it
Jim, I'm more comfortable with more frequent changes as well, but it really does depend on the vehicle, application and operating environment. I think the best frequency is the one that the owner is most comfortable with as long as it is within the manufacturer's specs. That being said, BMW and others have been pushing change-intervals pretty darn far in what I suspect is more of a desire to suggest that the total cost of ownership is lower than doing more frequent changes....I disagree on 15000 oil changes on vehicles, if you plan on keeping more frequent changes should be done...
I'm just coming up to the 5,000 mile mark on my RTW which means that the oil is now 4,400 miles old (after the 600 mile running-in check oil-change). I've got a ton of non-motorcycle travel scheduled between now and the end of riding season here so I suspect that I'll only have around 6,000 miles on the bike before doing the fall lay-up oil-change (about the same as your intended schedule). My plan is to send a sample of the old oil for analysis to see two things:
1 - If the acid build-up is sufficient to warrant continuing with the recommended annual oil-change frequency. I don't like leaving old oil in an engine over the winter due to the acids.
2 - Overall condition of the oil for doing it's job. Part of the analysis is that it will come back with a suggested change interval.
I'll try to remember to report back hear those finding in late October / November.
...Shop that worked on my Mini Cooper frowned on extended oil changes especially with a turbo engine...
Most cars, SUVs and trucks put very little load on a fully-synthetic oil, but that changes with forced-induction and motorcycles, especially wet-clutch bikes. The biggest issue with fully-synthetic oil isn't the oil going bad it is a) filtration and b) degradation of the additive package. Some vehicles will allow a filter change without having to change the oil which I like as I am more worried about the filtering ability after a long duration than the life-span of a fully-synthetic oil. The analysis will identify if the filtering, additives and oil are still okay.
The newer ones (for some time now) are built with water-cooling for the turbo bearings that will continue to do it's job after the engine is turned off. The old ones would fry the bearings and coke-up the oil-lines if one didn't adhere to rule of letting the engine idle for a short while before shutting it off. There used to be an aftermarket "Turbo-timer" that you could buy and install that would keep the engine running for say 1 minute after you turned off the ignition. Since the manufacturers wised up the need for those devises has dried up.FWIW, IMO, turbo engines need a minute to "spool" down before the engine shuts off and the oil stops pumping.
Never had a gas turbo, maybe that "problem" has been addressed in the newer gas models where perhaps a driver came off a "normally aspirated" engine.
Those tiny needle bearings are sensitive.
OM