Toyota Motor Corp.'s new Prius hybrid won more than 80,000 orders even before going on sale, prompting departing President Katsuaki Watanabe to call it the carmaker's "savior." Investors don't share his faith.

"Toyota shouldn't be happy just because Prius orders are going up," said Yuuki Sakurai, general manager of financial and investment planning at Fukoku Mutual Life Insurance Co. "What it should worry (about) now is Lexus and high-end customers may shift to driving a Prius."

Toyota slashed production costs for the Prius by 30 percent in response to dwindling sales of bigger, more lucrative models. Lexus sales in the U.S. have fallen 37 percent this year through May, mirroring an overall plunge in demand caused by falling wages and rising unemployment.