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.

BorgWarner (BWA) is progressing from last week’s rating of B (“buy”) as the company improves to an A (“strong buy”) this 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. The stock price has risen 5.4% over the past month, better than the 1.7% decrease the S&P 500 has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of BWA stock.

This is a strong week for Dorman Products, Inc. (DORM). The company’s rating climbs to A from the previous week’s B. 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.

China Automotive Systems, Inc. (CAAS) is bumping up its rating from a C (“hold”) to a B (“buy”) this week. 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 Holdings Corp (FDML) improves from a C to a B rating this week. 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.