The average retail price of a used Class 8 vehicle in July inched past $90,000 to tower over the year-ago price, but it also dipped slightly from June to extend the market’s ongoing softening, ACT Research reported. July’s average retail price was $91,928 compared with $64,226 a year earlier. But it also was down 1% from June’s $92,734 — the fourth consecutive sequential decline. ACT Vice President Steve Tam said the softer demand for used trucks comes as freight rates and the economy slow.