This week, five Oil and Gas stocks are improving their overall rating on Portfolio Grader. Each of these rates an “A” (“strong buy”) or “B” overall (“buy”).

NGL Energy Partners (NYSE:NGL) is progressing from last week’s rating of B (“buy”) as the company improves to an A (“strong buy”) this week. NGL Energy Partners owns and operates a vertically-integrated propane business. In Portfolio Grader’s specific subcategories of Earnings Momentum and Sales Growth, NGL also gets A’s. Shares of NGL have increased 7.6% over the past month, better than the 0.7% decrease the S&P 500 has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of NGL stock.

Exxon Mobil (NYSE:XOM) is bettering its rating of C (“hold”) from last week to a B (“buy”) this week. Exxon Mobil operates petroleum and petrochemicals businesses on a worldwide basis. The stock has a dividend yield of 2.3%. The stock currently has a trailing PE Ratio of 9.1. For more information, get Portfolio Grader’s complete analysis of XOM stock.

TC PipeLines‘s (NYSE:TCP) gets a higher grade this week, advancing from a C last week to a B. TC PipeLines LP acquires, owns and participates in the management of energy infrastructure businesses in North America. The stock’s dividend yield is 3.1%. Shares of the company have gone up 1.3% from a month ago. 

For more information, get Portfolio Grader’s complete analysis of TCP stock.

Saratoga Resources (AMEX:SARA) shows solid improvement this week. The company’s rating rises from a C to a B. Saratoga Resources is an independent oil and natural gas company engaged in the production, development, acquisition and exploitation of natural gas and crude oil properties. The stock has a trailing PE Ratio of 7.6. Shares of the company have shot up 6.7% from the previous month. For more information, get Portfolio Grader’s complete analysis of SARA stock.

ZaZa Energy (NASDAQ:ZAZA) boosts its rating from a C to a B this week. Toreador Resources is an independent international energy company engaged in the acquisition, development, exploration and production of crude oil. For more information, get Portfolio Grader’s complete analysis of ZAZA 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.