Yes, you can mix them.
The engine uses 5W30. It can be synthetic or conventional.The engine uses 5W30. It can be synthetic or conventional.
Yes, without any issues. That's what synthetic blend oils are (better than conventional oil, not quite as good as pure synthetic).
Yes, you can mix them.
No, I would not recommend using synthetic in an engine this old. Use a good 10w40 conventional oil.
No it is fine to switch back to regular oil.
conventional. I wouldn't put synethic in it unless it has already had it in the engine. Synthetic is mostly used in high performance or new vehicles. Synthetic won't do anything for an older engine
It can be. The 5w20 is the weight of the oil which you can buy conventional or synthetic. If it is synthetic it will say so right on the container. If it does not say synthetic it is conventional oil.
Yes, you can even mix synthetic with conventional oil.
Yes, you can even mix them together with no problems.
You can use synthetic is any internal combustion engine. You can even mix it with conventional oil.
It is always best to use the oil recommended by your vehicle manufacture. If you are considering the difference between Synthetic oil and Conventional (pumped from the ground); if your owner's manual says to use synthetic, you need to use synthetic. But if your engine was designed around conventional, then you can upgrade to synthetic. Synthetic has advantages as being better at cleaning and protection your engine, but if you have a higher mileage vehicle, synthetic can cause leakage of the gaskets and oil seals.
It is a combination of synthetic oil and conventional oil.