The grades of four auto parts stocks are on the rise this week on Portfolio Grader. Each of these stocks is rated an “A” (“strong buy”) or “B” overall (“buy”).

BorgWarner (BWA) is making headway this week, with the company’s rating improving to an A (“strong buy”) from a B (“buy”) last week. BorgWarner is a supplier of highly engineered systems and components, mainly for powertrain applications. In Portfolio Grader’s specific subcategory of Equity, BWA also gets an A. For more information, get Portfolio Grader’s complete analysis of BWA stock.

Dorman Products, Inc. (DORM) improves from a B to an A rating this week. Dorman Products supplies automotive replacement parts, fasteners, and service line products primarily for the automotive aftermarket. For more information, get Portfolio Grader’s complete analysis of DORM stock.

This week, China Automotive Systems, Inc. (CAAS) is showing significant improvement as the company’s rating hops from a C (“hold”) to a B (“buy”). 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.

Federal-Mogul Corporation (FDML) earns a B this week, jumping up from last week’s grade of 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.