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MPC vs. PSX: A Closer Look at Two Strong Refining Powerhouses

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Key Takeaways

  • MPC combines refining strength with high-return projects and expanding MPLX operations.
  • PSX offers diversified exposure across refining, midstream, chemicals and renewable fuels.
  • MPC trades at a lower valuation and has stronger projected 2026 EPS growth than PSX.

Marathon Petroleum Corporation (MPC - Free Report) and Phillips 66 (PSX - Free Report) are two major U.S. downstream energy companies with broad operations across refining and related businesses. MPC combines its large refining and marketing network with midstream operations through MPLX and renewable diesel, giving it exposure to multiple parts of the energy value chain. Phillips 66 has a more diversified portfolio spanning Refining, Midstream, Chemicals, Marketing and Specialties, and Renewable Fuels.

Both companies are benefiting from a constructive refining environment while pursuing operational improvements and disciplined capital allocation. MPC is also investing in projects aimed at improving refinery yields, while Phillips 66 continues to expand its integrated midstream network and reduce debt. With both stocks offering different strengths, a closer comparison can help determine how they stack up on fundamentals, growth prospects and valuation.

The Case for Marathon Petroleum Stock

Marathon Petroleum’s key strength is its large, integrated refining and logistics platform, which gives the company flexibility to source crude economically, optimize feedstocks and direct refined products toward attractive markets. In the second quarter of 2026, its Refining & Marketing business operated at 94% crude capacity utilization with a throughput of 2.9 million barrels per day, highlighting the scale of the system. Strong commercial and operational execution, along with higher crack spreads, supported the segment’s performance.

MPC also benefits from its focus on improving the profitability and competitiveness of its existing refineries rather than relying only on large expansion projects. The company is directing capital toward high-return investments at Galveston Bay, Robinson, El Paso and Garyville. The recently completed Robinson project added about 10,000 barrels per day of incremental jet-fuel capability, while the El Paso project enhanced specialty gasoline production. This approach should allow MPC to capture stronger margins while responding more effectively to changing product demand.

Further opportunities are scheduled through the end of 2027. The Galveston Bay project is designed to add a 90,000-barrel-per-day hydrotreater for higher-value ultra-low-sulfur diesel. At Garyville, planned investments are expected to increase crude throughput by 30,000 barrels per day and provide another 10,000 barrels per day of export-premium gasoline capacity. These projects could improve product yields, feedstock flexibility and access to domestic and export markets.

MPLX provides MPC with another important growth avenue outside refining. MPC is advancing natural gas and NGL infrastructure, and MPLX raised its 2026 growth-capital outlook to $2.9 billion as it accelerates Gulf Coast fractionation and related projects. Most organic growth capital is aimed at natural gas and NGL opportunities, particularly in the Permian and Marcellus. This expansion can strengthen MPC’s integrated value chain and increase its exposure to relatively durable midstream cash flows while supporting higher distributions from MPLX.

The Case for Phillips 66 Stock

Phillips 66 has built a differentiated business model around its diversified downstream structure. Its portfolio spans Midstream, Chemicals, Refining, Marketing and Specialties, and Renewable Fuels, reducing its dependence on any single business line. The company also benefits from an integrated North American infrastructure network. Management says Midstream and Marketing provide more dependable cash flows, while Refining, Chemicals and Renewables offer additional commodity-driven upside, creating several earnings engines across the portfolio.

Operational improvement is another important strength. Phillips 66 has increased refinery clean-product yields, improved its cost structure and expanded nameplate capacity. The company’s midstream system has also grown substantially, with fractionation capacity exceeding 1 million barrels per day and record LPG export volumes. At the same time, its renewable operations include one of the world’s largest renewable diesel facilities, giving PSX additional exposure beyond conventional refining.

Midstream offers a sizable pipeline of future opportunities. Dos Picos II has reached full production, while Phillips 66 plans the 300-MMcfd Zeus gas plant and a 100,000-barrel-per-day Coastal Bend NGL fractionator. Meanwhile, the Western Gateway project would create roughly 1,300 miles of refined-product infrastructure with an initial design capacity of 230,000 barrels per day. The project is intended to link Central Corridor and Gulf Coast refining assets with western marketing markets and is targeted for completion in 2029, subject to approvals.

Chemicals provide another potential source of growth. Chevron Phillips Chemical is progressing the Golden Triangle Polymers project in Texas, which is expected to reach full operations in 2027. Combined with further midstream investment and continued refinery optimization, these projects could broaden PSX’s earnings base and strengthen the contribution from businesses outside traditional refining over the coming years.

Price Performance Comparison

In the past six months, shares of MPC and PSX have surged 82.7% and 54.5%, respectively.

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Image Source: Zacks Investment Research

Valuation Comparison

From a valuation perspective — in terms of forward price-to-earnings ratio — Marathon Petroleum is trading at a discount of 7.51X compared with Phillips 66’s 9.62X.

Zacks Investment Research
Image Source: Zacks Investment Research

EPS Estimates

According to the Zacks Consensus Estimate, MPC’s earnings are set to rise 452.8% year over year in 2026.

Zacks Investment Research
Image Source: Zacks Investment Research

The same for PSX’s 2026 EPS indicates a year-over-year increase of 339.1%.

Zacks Investment Research
Image Source: Zacks Investment Research

Conclusion

Marathon Petroleum and Phillips 66 both offer solid exposure to a favorable refining backdrop. PSX benefits from a diversified portfolio spanning refining, midstream, chemicals, marketing and renewable fuels, along with several projects that could broaden its earnings base, justifying its Zacks Rank #1 (Strong Buy).

However, MPC appears better positioned overall, supported by its integrated refining and logistics platform, refinery-upgrade projects and expanding MPLX operations. MPC has also gained 82.7% over the past six months compared with PSX’s 54.5% and trades at a lower forward P/E of 7.51X compared with 9.62X. Its expected 2026 EPS growth of 452.8% also exceeds PSX’s 339.1%, justifying its Zacks Rank #1. While both stocks currently carry the same rank, MPC emerges as the clear winner in this comparison.

You can see the complete list of today’s Zacks #1 Rank stocks here.

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