The grades of four auto parts stocks are better this week, according to the Portfolio Grader database. Every one of these stocks has an “A” (“strong buy”) or “B” overall (“buy”) rating.

This week, Dorman Products, Inc. (DORM) is showing good progress as the company’s rating jumps from a B (“buy”) last week to an A (“strong buy”). Dorman Products supplies automotive replacement parts, fasteners, and service line products primarily for the automotive aftermarket. In Portfolio Grader’s specific subcategory of Equity, DORM also gets an A. For more information, get Portfolio Grader’s complete analysis of DORM stock.

China Automotive Systems, Inc. (CAAS) ups its rating to a B (“buy”) this week after earning a C (“hold”) in the week before. China Automotive System designs, markets, and sells custom-designed stained glass and leaded glass artifacts. For more information, get Portfolio Grader’s complete analysis of CAAS stock.

BorgWarner (BWA) boosts its rating from a B to an A this week. BorgWarner is a supplier of highly engineered systems and components, mainly for powertrain applications. For more information, get Portfolio Grader’s complete analysis of BWA stock.

Federal-Mogul Holdings Corp’s (FDML) ratings are looking better this week, moving up to a B from last week’s C. Federal-Mogul supplies products, services and solutions to automotive, light commercial, heavy-duty truck, off-highway, agricultural, marine, rail, and industrial markets. For more information, get Portfolio Grader’s complete analysis of FDML stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.