I did back in 2001 , and have used 100 % synthetic oil in my 1995 Ford
Explorer ever since . As long as your engine is healthy ( doesn't leak or burn
any oil ) I had about 51,000 miles on my engine when I did so I knew the
piston rings had " worn in " As long as you use the same weight of engine
oil that the manufacturer recommends and it meets the manufacturers
specifications ( P.S. I'm not a mechanic / technician )
Yes, you can even mix them.
yes
Yes, you can even mix them.
No, you can even mix synthetic with conventional oil. It will do no harm at all.
No it is fine to switch back to regular oil.
yes, if the car manufacturer dictates that regular oil is acceptable. If your car requires synthetic oil as dictated by your owner's manual, then DO NOT use regular oil. May void warranties if your car is still covered.
If you have kept regular oil changes, no prep is required. Just go and put the synthetic oil in.
yes it is fine but of course synthetic is the best to use if you can. Double check your oil requirements with your owner's manual. If it states that normal oil is okay, then go ahead. If your owner's manual dictates Synthetics, then DO NOT switch.
synthetic to conventional - ok conventional to synthetic - no
its the same process as changing synthetic oil, except you use regular oil.
Synthetic oil or a blend of Synthetic and regular oil is much better for your vehicle than regular oil alone. Synthetic oil is MUCH more expenshive. If you change your regular oil every 3 months or 3,000 miles I will be fine.
Yes, you can. It is even sold as a Synthetic Blend.