15s to 17s tire size dilemma

[Virg464]

I went with these:
https://atturo.com/tire/az800/6771

275/55R17
235/60R17

Those were to be really close to 235/70/15 and 275/60/15. They are a little taller - worked ok on my Fury, a little tight on the Charger. The fronts aren't as wide as the Firestone Indy500's I had in 235/70/15 even though they should have been on paper. The wider ones are too tall however. These are performance SUV tires but on a C body that's just fine.

If you guys already know this I apologize, not trying to talk down to anyone. I was always told that the first number in the series is the tire width in mm (not the tread) and the second is called the aspect ratio (percentage of the width) which is the sidewall height. So, (275/55R17) would be 275mm x 55% = 151.25 mm sidewall. 151.25 X 2 = 302.5 / 24.5 = 11.9" of tire sidewall. Add the wheel dia of 17" + 11.9" = 28.9" should be close to the overall tire height (dia)?

 

[33 IMP]

If you guys already know this I apologize, not trying to talk down to anyone. I was always told that the first number in the series is the tire width in mm (not the tread) and the second is called the aspect ratio (percentage of the width) which is the sidewall height. So, (275/55R17) would be 275mm x 55% = 151.25 mm sidewall. 151.25 X 2 = 302.5 / 24.5 = 11.9" of tire sidewall. Add the wheel dia of 17" + 11.9" = 28.9" should be close to the overall tire height (dia)?

That's what tire size calcator says...28.9 tall.

 

[furious70]

Yes and 28" would work better on my charger and 27" up front. Driver's side would rub the front fender wheel lip molding when backing up at a turn