YES! "Regular" oil is what is mixed with synthetic to make semi-synthetic. Try to use the same brand. I've heard it's not good to mix the different additives that different companies use.
Yes but once you do there is no turning back and no mixing regular motor oil ever again with the synthetic oil....only straight synthetic....or use semi synthetic....now that can be mixed with regular motor oil in a pinch.
its the same process as changing synthetic oil, except you use regular oil.
Yes you can use a synthetic blend or 100% synthetic.
10w40 Semi Synthetic Oil
Yes
i use Castrol Semi synthetic oil, Which is good for the engine
The oil kind off depends on temperature and mileage if you car is below 100K miles in regular climate use 10-30 semi synthetic (best for the price) if you in a hot climate like Arizona use 10-40 semi synthetic if you car is over 100k but below 200k use 10-40 semi synthetic for regular climate 20-50 for hot then every thing above 200k use 20-50 semi synthetic and remember change it every 3k its also good to change 4 quarts of transmission fluid every 3rd oil change. (just regular transmission fluid) No need of changing transmission filter but you can clean the pan every 60k
You can use synthetic as long as you use the exact weight Ford recommends.
5w/30 fully synthetic or 10w/40 semi synthetic.
There are available many semi- and fully-synthetic oils which are formulated for diesel engines.
If it has the right rating, nothing.
use it, it is ok to mix