do jet (turbines) engines need to have an oil changes???

 

My uneducated answer would be yes.

There are amny moving parts, built not too unlike a car's engine, which needs lubrication. So just as any other motor would need lubrication (automotive or otherwise) so does a jet engine.

 

I would expect so. Although, I expect the intervals are slightly different than for your xA.

 

most use foil bearing and use assembly lube and or grease from everything i've read.

some of the output shafts used for propellers and the like need and use gear oil in their reduction gear gearboxes

 

They aren't throwing in 10w 30 motor oil but ALL engines need lubrication.