It’s a good benchmark, IMO. It will vary a bit based on the design of the wheel and the dimensions of the tire that you want to run. IIRC, most 17x8 wheels will start to make contact with suspension components with >5.7” backspace or so. Usually a small spacer can solve that though.
Im resisting the urge to toss this question to our resident wheel scientist
@72bluNblu because he’s already been unreasonably generous with his time answering my questions. But I will pass along the conclusion that I wish I had accepted MUCH earlier on:
If you can adjust your expectations of aesthetics, (and since you’re looking at 17s you may be there already)the world opens up if you opt for 18” wheels. The extra inch of ID allows much more backspace and therefore much more tire. Also, the range of tire options is much better for 18s than 17s.
If you have your doubts that a “modern” wheel size can look good, you’re not alone. I’m now convinced that whether they look amazing or ridiculous depends entirely on picking the right style. His Demon is (IMO) one of the slickest and most purposeful looking Abodies on the forum with 18” Enkei RPF1 wheels and a surprising amount of rubber stuffed perfectly under the fenders. The RPF1s are a classic go-to track day kind of wheel style that has been around for decades and the style just works (IMO). This will depend entirely on personal taste of course. I’m just encouraging you to keep an open mind.
