Chrysler and Jeep vehicles received higher marks in the latest University of Michigan American Customer Satisfaction Index. The survey, which polls consumers who have had their vehicles between six months and three years, also shows Dodge lost some ground.All Chrysler brands scored below average on the Index’s 100-point scale. Average for all brands was 82 and Chrysler received the best score, coming in with an 80, an improvement of 1.3 percent that left it tied with Ford and Pontiac. Jeep, though its grade rose an identical 1.3 percent, came in last with a 76. Dodge’s results dropped 2.5 percent, to 78, leaving it next-to-last in the rankings."If I were Chrysler, I would certainly be concerned," said Professor Claes Fornell said, who headed the study. Fornell noted Chrysler has also done poorly in other recent quality surveys.Lexus and BMW the chart with 87s. BMW improved 1.2 percent to pull even with the Japanese brand. Honda and Toyota both scored an 86. Buick and Cadillac, both of which dropped 1.2 percent, were the top American brands with 85s.Among American brands, Saturn had the largest improvement, gaining 4.9 percent to an 85 and giving it a three-way tie with Buick and Cadillac. Mazda and Kia were the most-improved imports; both gained 2.6 percent, rising to identical 80s and came in tied with Chrysler.Chevrolet was the biggest decliner in the survey, dropping 3.7 percent to 79. Lincoln-Mercury had the second-largest drop, 3.5 percent, but still came in above average with an 83.Responding to the survey, spokesman Ed Saenz said Chrysler has been working to improve customer satisfaction since being acquired by Cerberus last year.