Marathon Petroleum Provides Update Concerning Weather Impact on Garyville Refinery Operations

FINDLAY, Ohio, May 30, 2014 -Marathon Petroleum Corporation's MPC Garyville refinery was impacted by a tornado that occurred on May 28. As a result of this severe weather, the refinery experienced damage to a cooling water system that serves part of the refinery causing the No. 1 crude unit and other units to be taken off-line.

Based on MPC's initial assessment of the damage and necessary repairs, the crude unit is anticipated to be operational by mid-June. The company does not expect total refinery throughputs to be significantly impacted, projecting less than a 5 percent reduction to the company's prior throughput guidance for this quarter.

"The exceptional response of Garyville's employees and contractors, along with the support of the local and state emergency responders, is greatly appreciated," stated President and CEO Gary R. Heminger. "The workforce is to be commended for their outstanding efforts during the initial response phase."

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About Marathon Petroleum Corporation

MPC is the nation's fourth-largest refiner, with a crude oil refining capacity of approximately 1.7 million barrels per calendar day in its seven-refinery system. Marathon brand gasoline is sold through approximately 5,200 independently owned retail outlets across 18 states. In addition, Speedway LLC, an MPC subsidiary, owns and operates the nation's fourth-largest convenience store chain, with approximately 1,480 convenience stores in nine 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:
Beth Hunter (419) 421-2559
Geri Ewing (419) 421-2071

Media Contacts:
Angelia Graves (419) 421-2703

This press release contains forward-looking statements within the meaning of federal securities laws regarding MPC. These forward-looking statements relate to, among other things, expectations, estimates and projections concerning the business and operations of MPC. You can identify forward-looking statements by words such as "anticipate," "estimate," "expect," "project," "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 company's control and are difficult to predict. Factors that could cause MPC's actual results to differ materially from those in the forward-looking statements include: the availability of materials and labor, delays in obtaining any necessary third-party approvals, and other risks customary to maintenance and construction projects; the reliability of processing units and other equipment; volatility in and/or degradation of market and industry conditions; the availability and pricing of crude oil and other feedstocks; consumer demand for refined products; transportation logistics; other risk factors inherent to MPC's 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, 2013, filed with the Securities and Exchange Commission. 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 results.