Exhibit 99.1

Marathon Petroleum Corporation Reports Fourth-Quarter and Full-Year 2012 Results

FINDLAY, Ohio, Jan. 30, 2013 – Marathon Petroleum Corporation (NYSE: MPC) today reported 2012 fourth-quarter earnings of $755 million, or $2.24 per diluted share, compared with a loss of $75 million, or $0.21 per diluted share, in the fourth quarter of 2011. For the fourth quarter of 2012, earnings adjusted for special items were $760 million, or $2.26 per diluted share, compared with a loss adjusted for special items of $75 million, or $0.21 per diluted share, in the fourth quarter of 2011.

Earnings were $3.39 billion, or $9.89 per diluted share, in 2012, compared with $2.39 billion, or $6.67 per diluted share, in 2011. For 2012, earnings adjusted for special items were $3.35 billion, or $9.79 per diluted share, compared with $2.41 billion, or $6.72 per diluted share, in 2011.

“Marathon Petroleum Corporation’s commitment to safety, operational excellence and strong financial performance enabled us to continue to enhance shareholder value through strategic investments in the business and return of capital to our investors,” said Gary R. Heminger, president and chief executive officer. “The expansion of our share repurchase authorization announced earlier today reflects our strategic intent to achieve balance and discipline in our use of investor capital. We will continue to drive value by making carefully considered investments that position us to take advantage of evolving crude oil and product opportunities, along with a consistent and focused return of capital to our shareholders.”

Heminger noted that in 2012, MPC returned $1.35 billion to shareholders through two accelerated share repurchase programs and another $407 million through dividends. MPC’s stock at year-end 2012 reflected an 89 percent increase in value relative to year-end 2011. With dividends, total shareholder return for 2012 was 93 percent.

Significant Accomplishments

Heminger said that MPC’s excellent financial results in 2012 were matched by its safety performance. “At MPC, we regard health and safety as core values,” he said. “When our operations are safe and our people healthy, we know our results will be that much better. That certainly has held true as MPC employees and contractors helped us achieve our best-ever safety performance in 2012, an accomplishment of which we are all very proud.”

Heminger highlighted the initial public offering (IPO) of midstream master limited partnership MPLX LP (MPLX) as an important milestone for MPC in 2012. MPLX common units began trading on the New York Stock Exchange on Oct. 26. “With its ownership of a majority interest in some of MPC’s core midstream assets, MPLX represents an attractive investment for unitholders and MPC shareholders alike,” he said. “With multiple avenues for expansion, MPLX will be our primary vehicle to grow our midstream business and to participate in the infrastructure investments needed to address the changing North American energy landscape. MPC’s ownership interest in MPLX will allow MPC shareholders to participate in the value created by growing the fee-based, stable, cash-flow business of MPLX.”

As 2012 came to a close, MPC’s Detroit Heavy Oil Upgrade Project (DHOUP) was complete and fully operational. “DHOUP represents a landmark achievement for MPC,” Heminger said. “This $2.2 billion investment increases our capacity to process heavy crude oils, which are expected to be price-advantaged well into the future, and enhances our flexibility to process a wide slate of crude oils.”

Heminger also remarked on DHOUP’s execution as notable. “We completed this project not only on budget and on schedule, but with world-class safety performance, including no lost-time injuries since we started construction in mid-2008,” he said. “I am proud of the project team and all our employees and contractors whose sustained effort over the years resulted in such a successful outcome.”

In October, MPC announced that it had signed a definitive agreement with BP to acquire its 451,000 barrel-per-calendar-day refinery near Galveston Bay in Texas City, Texas, and related midstream assets and branded jobber contracts for approximately $598 million, plus inventories estimated at $1.1 billion. The agreement also contains an earnout provision under which MPC could pay up to an additional $700 million over six years, subject to financial performance and other conditions. The transaction will be funded with cash on hand, and is expected to be accretive to earnings in the first year of operation. “The Galveston Bay asset acquisition will be an excellent complement to our existing business,” Heminger said. “It will augment our ability to process a wide variety of crude oils, provide us additional access to refined product markets and give us a significant refining presence in the western Gulf of Mexico region, which will provide additional balance to our system. It also will increase our brand presence in the Southeast and significantly increase our participation in the chemicals value chain.” The refinery is one of the largest and most complex in the U.S., with a Nelson Complexity Index of 15.3. This will make it the most complex in MPC’s refining system.

Acquisition of the refinery and related assets is planned for completion Feb. 1.

MPC’s Speedway retail segment increased its store-count by about 7 percent in 2012 after acquiring 97 convenience stores in Indiana, Ohio and Kentucky. The acquisitions included 87 GasAmerica stores and 10 Road Ranger stores, bringing its total count to approximately 1,460 stores. “We continue to invest in this channel of distribution, which provides assured sales of gasoline manufactured at our refineries, and has generated stable cash flow from food and merchandise sales,” said Heminger. “In addition to strengthening its presence in key marketing areas, Speedway also achieved record segment income and EBITDA per store. At the same time, Speedway grew its merchandise same-store sales for the 15^th consecutive year and achieved its best-ever safety record.”

2013 Capital Plan

MPC’s capital investment plan for 2013 totals $1.6 billion, excluding the acquisition purchase price of the Galveston Bay refinery and related assets. The capital allocated to the Refining & Marketing segment is $1.02 billion for maintenance and value-accretive projects intended to capture additional value from changes in the market for crude oil, other feedstocks and refined products. The capital for these projects includes approximately $400 million for maintenance and synergy capital for the Galveston Bay refinery and related assets.

Capital allocated to the Speedway segment is $255 million, primarily for new stores, rebuilds, remodels and site acquisitions. Capital allocated to the Pipeline Transportation segment is $184 million, including MPLX. Capital allocated to corporate support activities is $160 million, primarily for upgrades to information technology systems.

Segment Results

Total income from operations was $1.19 billion in the fourth quarter of 2012 and $5.35 billion for full-year 2012, compared with a loss of $158 million and income of $3.75 billion in the fourth quarter of 2011 and full-year 2011, respectively.

Refining & Marketing

Refining & Marketing segment income from operations was $1.14 billion in the fourth quarter of 2012 and $5.10 billion for full-year 2012, compared with a loss of $182 million and income of $3.59 billion in the fourth quarter of 2011 and full-year 2011, respectively.

The $1.32 billion and $1.51 billion increases in Refining & Marketing segment income from operations for the fourth quarter of 2012 and full-year 2012 compared to the same periods in 2011 were primarily the result of a higher refining and marketing gross margin. The refining and marketing gross margin averaged $9.17 per barrel and $10.45 per barrel for the fourth quarter of 2012 and full-year 2012, respectively, compared with $0.39 per barrel and $7.75 per barrel for the fourth quarter of 2011 and full-year 2011, respectively. The main factors contributing to the increase in the gross margin were higher crack spreads and favorable crude oil acquisition costs. The favorable crude oil acquisition costs resulted primarily from a widening of the sweet/sour differential in the fourth quarter of 2012 and full-year 2012 compared to the same periods in 2011.

Speedway

Speedway segment income from operations was $77 million in the fourth quarter of 2012 and $310 million for full-year 2012, compared with $73 million in the fourth quarter of 2011 and $271 million for full-year 2011. The increases were primarily the result of a higher merchandise gross margin and a higher gasoline and distillates gross margin, partially offset by higher expenses associated with an increase in the number of stores.

Pipeline Transportation

Pipeline Transportation segment income from operations, including 100 percent of MPLX’s operations, was $72 million in the fourth quarter of 2012 and $216 million for full-year 2012, $34 million higher than in the fourth quarter of 2011 and $17 million higher than in full-year 2011, respectively. The increase in the fourth quarter of 2012 compared to the fourth quarter of 2011 was primarily due to an increase in transportation tariffs and pipeline affiliate income, partially offset by higher mechanical integrity expenses. The increase in full-year 2012 segment income from operations compared to 2011 primarily resulted from an increase in transportation tariffs, partially offset by higher mechanical integrity expenses and lower pipeline affiliate income.

Corporate and Special Items

Corporate and other unallocated expenses of $91 million in the fourth quarter of 2012 and $336 million for full-year 2012 were $4 million higher than in the fourth quarter of 2011 and $20 million higher than in the full-year 2011, respectively. The increase for the fourth quarter of 2012 compared to the fourth quarter of 2011 was primarily due to an increase in employee incentive compensation and nonrecurring project-related expenses, partially offset by a decrease in pension expenses associated with a pension plan amendment announced in the second quarter of 2012. The increase for full-year 2012 compared to full-year 2011 was primarily due to higher costs associated with being a stand-alone company for a full year in 2012, compared to half of the year in 2011, partially offset by a decrease in pension expenses associated with the pension plan amendment.

During the fourth quarter of 2012 and full-year 2012, MPC recorded pretax pension settlement expenses of $8 million and $124 million, respectively, resulting from the level of employee lump-sum retirement distributions occurring during the year. In addition, MPC recognized a pretax gain of $183 million in 2012 related to the sale of the company’s Minnesota assets in 2010.

Strong Financial Position and Liquidity

On Dec. 31, 2012, the company had $4.9 billion in cash and cash equivalents, an unused $2 billion revolving credit agreement and a $1 billion unused trade receivables securitization facility. The borrowing capacity on the revolving credit agreement will increase to $2.5 billion upon the acquisition of the Galveston Bay refinery and related assets to support additional core liquidity needs of the company. MPC intends to fund the Galveston Bay acquisition with cash on hand. The company’s credit facilities and cash position should provide it with sufficient flexibility to meet its day-to-day operational needs, and its strong performance should enable it to continue its balanced and disciplined approach to investing in the business and returning capital to shareholders. As of Dec. 31, 2012, the company’s strong financial position was reflected by its debt-to-total capital ratio of 22 percent.

Incremental Share Repurchase Authorization

MPC’s board of directors today approved an additional $2 billion share repurchase authorization. The board also extended the remaining $650 million share repurchase authorization announced on Feb. 1, 2012, for a total outstanding authorization of $2.65 billion through December 2014.

Conference Call

At 10 a.m. EST today, MPC will hold a webcast and conference call to discuss reported results and provide an update on company operations. Interested parties may listen to the conference call on MPC’s website at http://www.marathonpetroleum.com by clicking on the “2012 Fourth-Quarter Financial Results” link. Replays of the conference call will be available on the company’s website through Wednesday, Feb. 13. Financial information, including the earnings release and other investor-related material, will also be available online prior to the webcast and conference call at http://ir.marathonpetroleum.com in the Quarterly Investor Packet.

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About Marathon Petroleum Corporation

MPC is the nation’s fifth-largest refiner with a crude oil refining capacity of approximately 1.25 million barrels per day in its six-refinery system. Marathon brand gasoline is sold through approximately 5,000 independently owned retail outlets across 17 states. In addition, Speedway LLC, an MPC subsidiary, owns and operates the nation’s fourth-largest convenience store chain, with approximately 1,460 convenience stores in seven states. MPC also owns, leases or has ownership interests in approximately 8,300 miles of pipeline. Through subsidiaries, MPC owns the general partner of MPLX LP, a midstream master limited partnership. MPC’s fully integrated system provides operational flexibility to move crude oil, feedstocks and petroleum-related products efficiently through the company’s distribution network in the Midwest, Southeast and Gulf Coast regions. For additional information about the company, please visit our website at http://www.marathonpetroleum.com.

Investor Relations Contacts:

Pamela Beall (419) 429-5640

Beth Hunter (419) 421-2559

Media Contacts:

Angelia Graves (419) 421-2703

Jamal Kheiry (419) 421-3312

References to Earnings

References to earnings or loss mean net income (loss) attributable to Marathon Petroleum Corporation (MPC) from the statements of income. Unless otherwise indicated, references to earnings, earnings adjusted for special items and earnings per share are MPC’s share after excluding amounts attributable to noncontrolling interest.

Non-GAAP Financial Information

In addition to earnings (loss) determined in accordance with GAAP, MPC has provided supplemental “earnings (loss) adjusted for special items,” a non-GAAP financial measure that facilitates comparisons to earnings forecasts prepared by stock analysts and other third parties. Such forecasts generally exclude the effects of items that are considered non-recurring, are difficult to predict or to measure in advance or that are not directly related to MPC’s ongoing operations. A reconciliation between GAAP earnings (loss) and “earnings (loss) adjusted for special items” is provided in a table on page 1 of this release. “Earnings (loss) adjusted for special items” should not be considered a substitute for earnings (loss) as reported in accordance with GAAP. We believe certain investors use “earnings (loss) adjusted for special items” to evaluate MPC’s financial performance between periods. Management also uses “earnings (loss) adjusted for special items” to compare MPC’s performance to certain competitors.

Forward-looking Statements

This press release contains forward-looking statements within the meaning of federal securities laws. These forward-looking statements relate to, among other things, MPC’s expectations, estimates and projections concerning MPC business and operations. You can identify forward-looking statements by words such as “anticipate,” “believe,” “estimate,” “expect,” “forecast,” “project,” “could,” “may,” “should,” “would,” “will” or other similar expressions that convey the uncertainty of future events or outcomes. Such forward-looking statements are not guarantees of future performance and are subject to risks, uncertainties and other factors, some of which are beyond the issuer’s control and are difficult to predict. Factors that could cause actual results to differ materially from those in the forward-looking statements include: volatility in and/or degradation of market and industry conditions; the availability and pricing of crude oil and other feedstocks; slower growth in domestic and Canadian crude supply; completion of pipeline capacity to areas outside the U.S. Midwest; consumer demand for refined products; transportation logistics; the reliability of processing units and other equipment; our ability to successfully implement growth opportunities; impacts from our repurchases of shares of MPC common stock under our stock repurchase authorization, including the timing and amounts of any common stock repurchases; our ability to successfully complete the acquisition of BP’s Texas City, Texas, refinery and related logistics and marketing assets; state and federal environmental, economic, health and safety, energy and other policies and regulations; other risk factors inherent to our industry; and the factors set forth under the heading “Risk Factors” in MPC’s Annual Report on Form 10-K for the year ended December 31, 2011 filed with the Securities and Exchange Commission (the “SEC”). In addition, the forward-looking statements included herein could be affected by general domestic and international economic and political conditions. Unpredictable or unknown factors not discussed here or in MPC’s Form 10-K could also have material adverse effects on forward-looking statements. Copies of MPC’s Form 10-K are available on the SEC website, at http://ir.marathonpetroleum.com or by contacting MPC’s Investor Relations Office.

Consolidated Statements of Income (Unaudited)

Supplemental Statistics (Unaudited)

Supplemental Statistics (Unaudited) (continued)

Segment Earnings Before Interest, Taxes, Depreciation & Amortization (Segment EBITDA) (Unaudited)

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