The most common aerodynamic sleeper tractors showed some movement relative to each other in August. The Peterbilt 579 once again appeared to greatly outperform other models, but this is due mainly to the lack of any model-year 2013 579’s in our data this month, which artificially inflated the average. The same factor applied to the Kenworth T680. The Freightliner Cascadia continues to perform well despite its volume in the used market. Other models performed similarly to the recent trend.