Oh, that's a good idea. I actually have a friend who tilts their mirrors really far out so they can barely see their own car, and they did say that it helps them see more once they got used to it. Thanks for the reminder.
Many people recommend against seeing the corners of your vehicle in your side mirrors at all. The argument goes: Those are for seeing your blind spots, not for seeing behind you, and moving them way out will dramatically reduce your blind spot. Use the rear view mirror for, you know, the rear view.
It's taken me a long time to get used to, but it seems to work. I had to break myself of the habit of using just the side view mirror for changing lanes, to ensure there is no fast moving traffic overtaking. The biggest problem there is if someone is close up on you, like in stop and go. But I can lean over a bit to adjust the side angle then or when backing into parking.
The only problem is that things get a bit dicey if you don't actually have a rear view mirror (e.g. it's obstructed, or you're driving a vehicle that lacks one entirely, like a cargo van or box truck). This is a pretty rare case, though, and in those cases such vehicles typically have wide-angle mirrors that make it much easier to see both directly behind and to the side.
Mine are this same way. My side mirrors do a better job at covering the gap between my peripheral and my rearview this way, instead of overlapping as much with my rearview.
