235/55/17 is good on a 7 to 8 inch wide rim, can't be done on a 9 inch wide rim. When you are going 60 mph the speedo would read 61.4 mph. There is a wide range of tires available in this size across all types of tires.
245/50/17 has a limited available set of tires, many more than a year ago when I was looking for tires, 255/50/17 used to be sport truck only tires, but there are a couple of UHP all season tires available.
I have ran 245/45/17 on a 1.5 inch lowered Cougar, and height was okay, but a lot of open wheel well front and back (and still quite a bit on the top). 245/45/17 has a really large selection across UHP, Max performance, all season, touring, grand touring, etc. BUT they are almost an inch shorter.
I am now running 255/45/17 which are .5 inches shorter than stock, and I like the look. A pretty big gap all around, but equal. I have only lightly touched sidewall to fender with 5 people in the car, a trunk full of stuff, and hitting a big dip. This is with my 97 Mark VIII with coil springs.
255/45/17 on replacement coil springs:
225/60/16 and 215/60/16 tires are not wide enough for my 4.6 powered Cougar or Mark VIII. Forget about traction taking off, 1-2 shift, or even 2-3 shift. 245/45/17 still went up in smoke, 255 seems to be sufficient, I have to really pound on it to get them to spin (don't get me wrong, they still go up in smoke frequently) and only get 1-2 scratch when they are cold (but almost always trigger traction control 1-2 shift in Mark VIII).
I also don't need an all season tire, touring tire, or even a performance all season. I can and do run UHP summer. Any of the extreme performance or max performance are just low wear rating, and I am done with 10,000 miles tires, spending 700 bucks a year on tires. I looked for a asymmetrical tire that I liked, but couldn't find one, so once again I have directional tires, but same size front and back so I can at least go front to back rotation without dismounting them.