Hi. I purchased a new Civic Si Coupe. Any folks have any input on the vehicle’s performance, handling, gas mileage, or issues I should be aware of. Thanks in advance for your help.
I assume you did research on all of those things before purchasing your new car. The Civic Si Coupe is a nice combination of all the things you list. There, is that validation enough for you? Enjoy your new Honda.
Nice ride. Enjoy it. Sit with a cup of coffee some morning soon and read the owner’s manual through and through. It’ll give you lots of great info.
This is probably something you should’ve asked us about BEFORE you bought it. Fortunately you won’t get burned. Great little car and it looks good too. Once you’ve passed the break in period you can rip on that car all day long and not hurt it, so have FUN!
Expect performance parts to start becoming available in great quantities. I bet one of those things with a supercharger would be all sorts of fun 
Most of the information you seek is available in front of the passenger seat, in this little cubby hole you can put things in, called the glove box. In it, you have something from the factory(yes, they actually gave you something free with your car), it’s called the owner’s manual. Take the time to read it, but not while you are driving the car.
Enjoy it and don’t worry about it. Just take note at least in owners manual of maintenance schedule.