Introduced Thursday, Sept. 6, the index is based on the actual transaction prices of the more than 4 million vehicles that Manheim sells for clients at its 85 U.S. auctions, said Tom Webb, Manheim's chief economist and author of the report. He said the index considers elements such as mileage, seasonality, market segment and model mix.
Manheim started at a base of 100 in January 1995, Webb said. It reached an all-time monthly high of 117.4 this February. It started a downward trend after that, which continued through July. The index for August was 114, up from 113.8 in July.
Webb said the August index was up because strong used-vehicle demand deleted dealers inventories, creating more active bidding at auctions.