In an 8', you have wheel wells inside the trailer , so the trailer itself really axle isn't any wider than it is on a 7'. I originally was looking for a 7' wide, but the sales guy pointed that out to me; my original concern was being too wide for residential streets. So... an 8' trailer doesn't track any wider than a 7'... both widths are wider than a truck though, so you absolutely have to get extension mirrors of some sort on your truck so you can lane change safely.Im using a 6.5 X 16. Is the 8 foot wider trailer a deck over? Can't imagin an 8 ft non deck over, im already as wide as the lanes.