Ford ( F) and General Motors ( GM) are offering more incentives in a bid to prop up sales and fight what seems to be growing consumer reluctance to invest in a new automobile. The Wall Street Journal reported that Ford is offering payments of $500 to $1,500 to meet certain sales goals on the Ford F-150 pickup and the Ford Explorer. The company's new round of incentives follows GM's recent move to sweeten consumer rebates. The report indicated that in some parts of the country, dealers say GM is adding $500 in Memorial Day cash discounts, bringing rebates to $3,500 for the Chevy Suburban and Tahoe. Ford said the company is using the offers to boost sales in May and June, the Journal reported. Detroit's automakers began offering a series of incentives after the Sept. 11, 2001, terrorist attacks in the U.S., and some form of enticement has been used to get buyers onto dealers' lots ever since. Some data have indicated recently that the effect of incentives appear to be wearing off, but the automakers continue to look for ways to lower consumer costs. The Journal, citing Autodata Corp., reported that in April the Big Three -- GM, Ford and DaimlerChrysler ( DCX) -- were offering an average discount of $3,301 per vehicle, compared with $2,254 in April 2002.