If you put on a wheel and tire combo that is the same weight but of good quality then you are keeping your car the same in many respects.
If you put on a set of heavier wheels and tires you are downgrading your performance thus down grading the car no matter the cost.
If you put on a good set of wheels and tires that are lighter that stock you are upgrading the performance and at least keeping the quality the same or better.
There are many more variables to all this to consider but those are basic realities no matter what anybody has for an opinion as based on logic, reason and when you get down to the details, physics.
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Did you buy the car to show it off, enjoy the great things about it as is, enhance the performance...a bit of each one, all three?
You can do all the above if you take your time and the best thing you can do is post questions and learn from the answers so you are on the right track already