Medium and heavy truck sales were up 40% in August over the same period a year ago and up 14% from last month, according to figures compiled by Wards Communications.

Dealers sold 44,348 trucks with GVW ratings above 10,000 pounds during the month, up from August 2010 (31,554) and up from July 2011 (38,968).

Compared with August 2010, Class 8 trucks were up 71% (15,085, compared to 8,834). Class 7 sales were 3,795, up 25% from the 3,031 sold.

For the year, truck dealers have sold 309,960 trucks with GVW ratings above 10,000 pounds, up 30% from 238,503 in 2010. Class 8 sales have been 100,038, a 48% increase from the same period last year (67,680). Class 7 sales have been up 14% (27,640, compared to 24,333). Total sales of all classes have been up 13%, from 3,951,652 to 4,476,425.

Every class has been up, except for Class 4 (down 20%). The biggest increase has been in Class 8.