Every account of the outage at Exxon's Joliet refinery carries the same figure — about 11 million gallons of gasoline and diesel a day — and it is Exxon's, not the tape's. Exxon's own Joliet operations page still carried it on 18 September, four days after Reuters sourced the number to the company website. Divide by 42 and it is 261,905 barrels a day of finished product, against a plant that Exxon's 10-K and the federal refinery survey both rate at 267,000 barrels a day of crude. The same two documents say where most of those barrels go.
The survey Exxon files gives Joliet 26,000 barrels a day of coke and 17,100 of asphalt
Form EIA-820, as of 1 January 2026, rates Joliet at 267,000 barrels per calendar day and 278,100 per stream day. On adjacent lines of the same return the plant reports 26,000 b/sd of marketable petroleum coke, 17,100 b/sd of asphalt and road oil and 683 short tons a day of sulphur. Coke and asphalt alone are 43,100 ÷ 278,100 = 15.5% of the barrel, before a drop of jet fuel, LPG or refinery fuel gas. Exxon's 2026 facility profile lists those same products — LPG, asphalt, sulphur and petroleum coke — on the bullet immediately below the 11 million gallons, and puts the crude capacity on the bullet immediately above it.
Exxon's 2025 annual report prints the shape of its barrel. Worldwide Energy Products sales of 5,593 kbd split into gasoline and naphthas 2,290, heating oils, kerosene and diesel 1,791, aviation fuels 383, heavy fuels 220 and other energy products 910. Gasoline plus distillate is 4,081 ÷ 5,593 = 73.0%, and that is a sales book padded with product Exxon buys rather than refines, which skews light. No refinery the company owns turns 98% of a barrel into two products.
The diesel Joliet has stopped making is about 3.3 million gallons a day
EIA withholds gasoline and diesel volumes for individual plants, so nobody outside Exxon has Joliet's meter. It does publish the district's. In the week ended 11 September, Midwest refiners charged 4,241 kbd of crude and made 1,265 kbd of distillate, a yield of 29.8%. At that yield Joliet's 267 kbd makes about 79.6 kbd, or 3.34 million gallons a day — 6.3% of PADD 2 distillate production.
That yield is an assumption carrying the whole estimate, so here it is three ways.
Joliet at 267,000 b/cd against PADD 2 distillate production of 1,265 kbd, week ended 11 September; the yields applied and the gallon figures are ours
| Distillate yield | Joliet diesel | PADD 2 share |
|---|---|---|
| 25%, low case | 2.80m gal/d | 5.3% |
| 29.8%, PADD 2 actual | 3.34m gal/d | 6.3% |
| 32.0%, hydrotreater cap | 3.59m gal/d | 6.8% |
| 98.1%, the claim | 11.0m gal/d | 20.7% |
The middle row applies PADD 2's own distillate yield on crude inputs, 1,265 of 4,241 kbd, to Joliet unchanged; the plant's actual slate is not published. The low case is a round 25%. The third row is the ceiling set by Joliet's 89,100 b/sd of diesel desulphurisation charge capacity, restated on the plant's calendar-day basis. The last row is Exxon's 11 million gallons treated as though it were all distillate: the sheet calls it gasoline and diesel together, so that share is an outer bound on what the claim could imply, not an estimate.
A ceiling sits above it that needs no yield at all. Joliet's diesel desulphurisation units are rated 89,100 b/sd, which at the plant's own calendar-to-stream ratio of 0.9601 is 85,500 b/cd, or 3.59 million gallons — every barrel of ultra-low-sulphur diesel the refinery can finish. In the other direction, that 1,265 kbd is refiner and blender net production, so it counts biodiesel blended into the pool and flatters the yield.
Then the coincidence that lets the error pass a sniff test. 6.3% of Midwest distillate is almost exactly the 6% of Midwest refining capacity Exxon's fact sheet claims — a statement about crude, and a correct one. Two unrelated quantities landing on the same number is why nothing looks wrong at a glance.
The strongest case for 11 million gallons is that it means everything, not two products
Cracking adds volume, so a refinery ships more product than the crude it charges: 267 kbd in leaves as roughly 280 kbd, near 11.8 million gallons of everything, coke and asphalt included. Read as total output, the 11 million is about the right size and only the label is wrong. The label is the entire content of a diesel story, and a reader asking what a shut Midwest refinery does to diesel supply gets a number 3.4 times too big.
Diesel climbed 13.5% in the five weeks before the plant tripped
EIA's on-highway diesel average reached $6.285 a gallon in the week of 14 September. Most of that climb happened while Joliet was running: $5.257 on 10 August, $5.967 on 7 September, +13.5% across the five weeks before the outage. Midwest distillate stocks were 28.8 million barrels on 11 September, up 321,000 on the week. The move is a refining-margin story that predates this outage by weeks, and Joliet is regional risk layered on top of it.
Nor is this an Exxon earnings event. Joliet is 267 kbd of the 4,113 kbd of refining capacity Exxon carried at the end of 2025, 13.6% of its US kit. Five days down is 1.3 million barrels, 0.09% of the 3,979 kbd the company ran worldwide through 2025.
One week settles the size of the hole. EIA's 23 September weekly is the first to cover a full week with Joliet offline, and it should take something like 80 kbd off that 1,265. If Midwest distillate production instead drops by anything close to the 262 kbd the 11 million gallons implies, the estimate here is wrong and the tape was right.
Joliet's crude, asphalt, petroleum coke, sulphur and diesel desulphurisation capacities are the plant's own Form EIA-820 entries in the Energy Information Administration's capacity report as of 1 January 2026. Weekly Midwest crude inputs, distillate production and stocks, and the on-highway diesel average, are EIA's published series for the weeks ended 11 and 14 September. Refining capacity by site, worldwide throughput and the Energy Products sales slate are ExxonMobil's 2025 Form 10-K. The gallons-per-day claim, the 275,000-barrel capacity and the Midwest capacity share are Exxon's own, from its Joliet operations page and 2026 facility profile, both read on 18 September; Reuters sourced the figure to the company website on 14 and 17 September. Every yield, conversion and share derived from those inputs is ours.
