[Mr.ac]

Ah you been smoking the good stuff eh?

Let go over real quick tire size.
215/45/17.
First number is tire width. Bigger the number, wider the tire. And vice versa
Second number is side wall hight. Bigger the number taller the side wall. And vice versa.
Last number is rim/wheel size. Self explanatory.

As for your complaint, what you want is a wider tire. A 225/45/17 would be the fix for you. If you want more meat a 235/40/17.

Stretching tires is really a retarded move. Some would say it helps with tire flex, but really they are just retarded. If you wanted performance you'll just get better tires.

As for the idea of design, gas saving, performance, nah it's just the tire companies making a deal with the car company. Some retards would disagree saying the oem tires are a god send. Lol nope.