Originally Posted by doubleurx
The only issue with this compared to a narrower tire is driving in deep snow. On packed snow and ice, he will be better off - more sipes per sq inch of contact. I run the stock sizes 245/40/18 and they are awesome. We've had over 200 inches so far this season and no issues at all here.
First of all staying at stock size is definitely more optimal and what I was laughing about he put 255/45/18, then stated this is the size that Subaru should had put on for oem size while mentioning about the tires rubbing on the fender wells. If he had done his research that most people going to a 255 will put 255/35/18 to make sure the tires don't rub being a wider tire they will be also taller to begin with.
As for a wider tire u only gain traction in wet and dry conditions cuz the less weight displaced across the contact patch will give the tires less bite in compacted snow and ice.