I hate to say that's not true, but maybe that statement is a bit misleading. You have to be damn careful about back spacing. I went through quite a few options trying to get the tire and wheel combo that I wanted to fit my PT. If you've got the turbo, there's a slightly different setup on the front, and left front spacing is super critical. Where you have a problem is the clearance between the spokes on the wheel and your front calipers. I just went to a show two weekends ago and met a guy that had beautiful 18's on his, and he had to shave his calipers for them to fit, and you could barely fit a piece of paper between the wheel and the caliper!
So the secret is matching tire size and wheel size. It also depends on if you've lowered your PT too.
In my picture below, you can stack three quarters between the top of my tire and the bottom of the spring seat on the front struts. Thats right at 3mm clearance. Probably gets less when I'm running hard and heating up the tires, but that's as close as I want to come. I have plenty of clearance between the wheels and the front calipers as I went with the suggested offset (your measurements were in "backside spacing", versus the offset that most wheels are measured at).
Backside spacing is from the rim to the center of the mounting surface at the middle of the wheel. Offset is either a positive or negative number, and this refers to the mounting surface to the centerline of the wheel. So if you cut that wheel in half right down the middle vertically, how far in or out would the mounting surface be.
The only reason I know all this is from basically taking a course between PTCrew and Discount Tire's shop manager here in my town. He schooled me on all this and actually took around a dozen wheels and set them on my hubs so we could see what that all meant.
Here's my pic showing my clearance to my strut:
Mind you, that strut in my picture is a Tokico blue, not the factory Tokico black that came on the car. I didn't get any before shots as I didn't really care at the time....lol
I swear by Discount Tire. I had three shops on the same street here in Mooresville ready to sell me the retro Crager SS's. They were going to sell them to me, mount the tires and put the on car, and would have found out that they just wouldn't fit. I had the Cragar rep on the phone because I REALLY wanted those, and he was ready to sell me all kinds of silly spacers and such to make them work, but I still run my car on the track and could just see some of that crap flying off at halftrack and me ending up over the wall. No thanks, just give me a set of wheels that fit!!! Now I'll take the hub rings, those don't bother me, but all that other crap?!?
The guy at DT would NOT sell me the wheels I wanted. He told me I could go to any other place and get them, but he wouldn't sell them to me. He said we could make them fit and within a month I'd be hating them. So I followed his advice and I love the combination I ended up with.
17x7 MB Drifters with Falken Ziex Ze-912 all weather sport tires, 215/50R17, a little more meat on the ground, an excellent looking wheel, and no fit or performance issues!!! These are on a bolt pattern of 5x100 with an offset of .40.
No matter what anyone tells you, you can probably fit just about anything on there between 16" and 18", and could stuff 20's in there with some work. It's all up to you and what kind of ride you want (comfort wise), the stance you're looking for, and how much extra work you want to do to make them fit. The main thing is, get what you're happy with and ignore what all we say! You're adding new tires/wheels to please yourself or your significant other, so what we say doesn't matter for sh%t. lol
I like mine and don't give a damn what anybody else says. I went practical, got a bit more meat and a tall tire, like the ride and the look, and anyone who doesn't can just go soak in feces!
Also, I have to give a shout out to my Crewmates at PTCrew for the effort they put into learning me on this stuff. The guys and girls there were quite significant in helping me to make my decision to lower my PT and in fitting the proper tire and wheel size! Go PTCrew!!