This week, four auto parts stocks are improving their overall ratings on Portfolio Grader. Each of these stocks is rated an “A” (“strong buy”) or “B” overall (“buy”).

This week, BorgWarner (BWA) is showing good progress as the company’s rating jumps from a B (“buy”) last week to an A (“strong buy”). 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 pushed upwards for the past four days, reaching $61.15. For more information, get Portfolio Grader’s complete analysis of BWA stock.

Dorman Products, Inc. (DORM) is seeing ratings go up from a B last week to an A this week. Dorman Products supplies automotive replacement parts, fasteners, and service line products primarily for the automotive aftermarket. Shares of the stock have been trading at an exceptionally rapid pace, up threefold from the week prior. For more information, get Portfolio Grader’s complete analysis of DORM stock.

China Automotive Systems, Inc. (CAAS) is bettering its rating of C (“hold”) from last week 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) boosts its rating from a C to a B 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.