basedheero said:
Even though most people may not know the terms, its very easy to tell the difference between a muscle car and a sports car/supercar at a glance. As you mentioned, muscle cars are blockier looking American cars with a focus on pure horsepower.
Sports car and supercar on the other hand are a bit more ambiguous, as supercars are more or less a specific subset of super expensive and overpowered sports cars (Bugattis, McLarens, Lamborghinis, etc). Trying to define the separation from what should be in the supercar tag from what should just be sports cars could end up being a bit of a pain. As much as I like cars and can recognize a lot of them, the exact specifics for stuff under the hood and what exactly separates one class of car from another besides external differences is a bit beyond me, so someone else may be create a better distinction between the tags.
My overall impression is that "sports car" is a general term used for (usually expensive) high-performance cars. Supercar is the one coined (for marketing purposes) to describe those with even higher performance than the other sports cars. And American "muscle cars" used to be referred to as "supercars" too. Though over time the American version has "evolved" away from the usual "European" look towards the current "blocky sedan with overpowered engine design", and then at some point in time they switched terms over to "muscle car".
While the European "supercar" came to describe Lamborghini kind of "sports car" with a... 'Formula One' racecar-esque look with sleek curves. And also look 'short' and 'wide' (don't think they are actually that short height and width-wise, but the shape sort of make them look so). Then they started inventing new terms to distinguish the higher end models, like "hypercars" and what not.
So I suppose, if one wants to distinguish them, "sports cars" can be used for the general case, "supercar" for the Lamborghini-shaped ones, and
"muscle cars" for the blocky American ones with powerful engines (which may or may not also qualify for "sports car" depending on the model and exterior appearance). Problem is someone needs to populate those tags (there are probably a lot of untagged examples, at least for general "sports cars") and then write up workable Wiki defs for them.
And whoever decides to shoe in "hypercar" on top will deserve a very stern talking-to.
I don't... feel like doing so though, especially since it's not my area of expertise or interest. Hopefully someone will take up the torch.
Edit: Though... considering the existence of the Lamborghini tag (which is ironically more populated than all the above three tags combined)... maybe it would be probably easier to retire "supercar" entirely, and just tag sports car on top of Lamborghini or whatever appropriate model/manufacturer tag. Meanwhile muscle cars can be tagged muscle_car, and the ones that qualify as "sports cars" can also be tagged sports_car on top.