275/60/15 tires on stock Duster

Who wants to use a spacer? Maybe ordering a special wheel is the way to go, but My opinion is that you a pushing the envelope to far. 245 or 255 are better options

There’s absolutely nothing wrong with using spacers. As long as you have proper thread engagement on the lug nuts and stay hubcentric there’s no difference at all. And really, you can argue the hubcentric part as there are plenty of cars and wheels that aren’t, but that’s another discussion.

Pushing the envelope too far? If it fits without rubbing, it fits. You can get any size tire to rub if you don’t have the proper backspace.