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.

Dorman Products, Inc. (DORM) is progressing from last week’s rating of B (“buy”) as the company improves to an A (“strong buy”) this week. 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.

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.

This is a strong week for BorgWarner (BWA). The company’s rating climbs to A from the previous week’s B. 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. Shares of the stock have been changing hands at an unusually rapid pace, twice the rate of the week prior. 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.