I mistakenly had a regular oil change
and my handbook says to use
synthetic; should I have it flushed and
get an oils change with synthetic?
Have I damaged it? It's a 2013 Nissan
No, but I would get it changed back to synthetic as soon as possible, once you start using synth you should never go back to convential as oil leaks can start showing up. And I believe that this car recommends synth normally. So change the oil back to synth and the filter, I would worry about flushing the engine, sometimes that can do more damage than good.
(wouldn't worry about flushing the engine) is what tennisshoes is saying...
I would just get it changed at the next scheduled maintenance interval. Nothing to worry about. You can go back and forth between regular and synthetic oil without issue.
I have a 2016 miss a Altima 2.4, what kind of oil and what weight
Does my 210 Nissan Altima use regular oil?