I use only synthetic oil in my HD. I chnage the oil about every 5k miles. I have about 6K on this go around because I added an oil cooler and changed the filter when I did the cooler install. I was telling a guy about thisand he told me the military uses synthetic oils in their vehicles. He said that they never change the oil only the filter. He said they add oil when needed but they don't do a complete change. Does anyone know if this is accurarte? My source was pretty reliable but that just seems a little out there. I wouldn't do this on vehicles that I own but the military has a deeper source of income than I do.

Sorry if this topic has already been discussed. If it has please point me to the thread.

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For the 20 years I spent in the military we never changed the synthetic jet engine oil. We took samples periodically hardly ever had a bad analysis so now we don't even do analysis any longer. Same is true in the airline industry. Jet engine oil is change at the time the engine is changed. As for automotive engines, I can't comment on the Military practices but I can tell you that over the road fleets that use synthetic will go 100,000 miles between oil changes. Filters are changed periodically and oil analysis is used to determine the continued service ability of the oil. Very common these days.. Some even go till analysis indicates the oil is no longer serviceable. Way beyond 100,000 miles. If you can keep synthetic clean with a good filter system it virtually never wears out.

Filter systems on these vehicles will filter the oil down to 3 micron. ( a human hair is 70 micron)

Bear

 

The military uses 90% diesel engines from Humvees to much larger vehicles. They use regular 15w40 diesel oil manufactured from Safey Kleen. This oil is not synthetic.

Each vehicle in the fleet is on an oil analysis schedule. The oil gets analyized and still, the oil may/maynot get changed.

If the vehicle is serving in a war......then the analysis does not apply. They use their best judgement on whether to change or not to change.

 

I dont know if this is true or not but, it would make sense. I dont think the militarty is concerned with resale values of their vehicals. they need them to perform when needed. so if your being fired upon the last thing you need to worry about is" I need to change the oil in this truck". they must have a relieble sourse that tells them use synthetic and dont worry about wear. plus alot of heavy duty vehicals have larger oil capasitys then a harley or even a standard truck or car. and if it cuts down on downtime it makes sense to me.

 

Great information. Thanks! I wouldn't do it on my HD but it does make me feel a little better about not changing my oil right at a certain mileage.

 

I never changed the oil in our generators (Army) but you can be sure as heck that we did oil analysis every 2 months on them, even if they were not being used which was 98% down time.
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I don't think it makes any difference whether you use dino or syn oil. The extended oil change intervals depend the use of a by-pass oil filtration system in addition to the regular engine oil filter. Most by-pass filters filter particles down to <1 micron. The engine filters are still changed at recommend mileage intervals anda UOA is taken.

 

Used to work on F-4s & F-15s in USAF . Always used some MIL-Spec synthetic & never did an oil change. However; when the engine came out of the aircraft & was overhauled; part of the overhaul was to clean the parts & add new oil.
Of course we are compairing an aircooled internal combustion V-twin and a jet engine. Apples & oranges

Bottom line............synthetics have been around a long time & are cheap engine life insurance. Just my $ .02

 

Joe Minton in American Rider says it's a waste of money to change any more often than 10,000 miles when running synthetics, based on his experience of tearing down engines and checking for wear.

That would, however, definitely void a warranty that specifies 5,000 mile oil changes, or less in extreme conditions.

Here's an interesting link on the history of synthetics, which are nothing new :

http://www.synlube.com/synthetic.htm

which contains this:

1968
U.S. Army develops MIL-L-46167 specification, which can be satisfied only with PAO synthetic oil

 

Is this something you would do on your bike if it is out of Warranty?