API vs EIA Inventory Reports, Explained

1. The verdict first: two reports, side by side

Every week, the US oil market gets the same story twice. On Tuesday afternoon the American Petroleum Institute publishes its Weekly Statistical Bulletin. On Wednesday morning the Energy Information Administration publishes the Weekly Petroleum Status Report. Both describe the same week ending the previous Friday. They frequently disagree, and the disagreement is not an error in either one. They are two separate surveys with two separate tallies, and the table below is the whole comparison in one view.

Read the rest of this page as the footnotes to that table. Why two surveys of the same week disagree, how large the disagreement can get, and how to use a Tuesday preview without mistaking it for the Wednesday verdict.

2. Same forms, same week, different tally

The strangest fact in this comparison is how much the two surveys share. The API states, in its own frequently asked questions, that it collects an exact copy of the data submitted to the EIA, that it uses the same EIA weekly survey forms, and that it follows the EIA's collection schedule and submission deadline. The respondents are the same population: US refiners, operators of bulk storage and blending terminals, pipeline companies, and importers, reporting stocks and operations for crude oil and the major products. If the inputs are that similar, why do the outputs differ?

Four reasons, in rough order of importance. First, participation: reporting to the EIA is mandatory, reporting to the API is voluntary, so the respondent sets are close but not identical, and a large terminal that reports to one and not the other shifts that week's tally. Second, timing: a submission that misses one organization's internal cutoff can still land in the other's, and in a survey assembled over a weekend that margin matters. Third, estimation: neither survey hears from the whole industry. The API states that both it and the EIA cover roughly 90 percent of the industry and publish estimates, and two different estimates of the missing tenth produce two different totals. Fourth, revision practice: the EIA benchmarks its weekly estimates against fuller monthly surveys and restates history; the API bulletin is a snapshot that stands as published. The two reports are best understood as two measurements of the same physical week, taken with slightly different instruments.

3. A worked week: October 2026, when distillates flipped sign

The week ending October 16, 2026 shows every element of the comparison in a single episode. The API published first, on Tuesday, October 20, and its figures, as reported in market coverage that evening, were a draw across the board: crude stocks down 4.93 million barrels, gasoline down 2.0 million barrels, distillates down 2.6 million barrels. A reader who stopped there had a uniformly bullish picture: inventories falling everywhere.

The EIA published the next morning, Wednesday, October 21, for the same week. Crude drew 3.060 million barrels, against a consensus expectation of about 0.82 million. Gasoline drew 2.952 million barrels, a larger draw than the API had shown. And distillates, the product the API had down 2.6 million, came in as a build of 1.675 million barrels, against a consensus expectation of a draw of about 1.162 million. The arithmetic of the disagreement:

Same week, same forms, same industry: a 1.87 million barrel difference on the crude change, and on distillates a disagreement about whether stocks rose or fell at all, 4.28 million barrels wide. Neither figure is a fabrication; they are two estimates built from respondent sets that overlap almost completely but not entirely, each grossing up its own sample to a national total. Distillate stocks are a smaller, more regionally concentrated pool than crude, so a coverage difference shows up there first. The episode is the standing answer to the reader who asks why the two reports cannot simply be reconciled: there is nothing to reconcile. There are two surveys, and the official one publishes second.

4. Which one moves the market, and why the preview still matters

The EIA report moves prices more, and market coverage of the weekly releases says so in nearly those words: the EIA figures are treated as the official benchmark and typically drive the bigger move. The reasons are structural. The survey behind the EIA report is mandatory, so its coverage does not depend on goodwill. The report carries the detail the market's models actually consume: crude production estimates, product supplied as the demand proxy, stocks by refining district, Cushing inventories for the WTI delivery point, and the Strategic Petroleum Reserve, none of which the API headline provides. And the release is free, simultaneous, and fixed at 10:30 a.m. eastern in the middle of the trading morning.

The API bulletin matters for a different reason: it arrives 18 hours earlier, after the Tuesday close, and it usually gets the direction of the crude figure right. Prices move on it in the evening session, positioning builds around it, and Wednesday morning then becomes a second trade: the EIA figure against both the consensus and the API preview. When the EIA confirms the API, the move extends. When the EIA contradicts it, as it did on distillates in October 2026, the reversal is sharp precisely because the preview had concentrated the positioning. The two reports are complements in the market's week, which is why the EIA report schedule treats them as appointments in a single calendar.

5. How to use both reports: a reading protocol

• Tuesday evening: read the API as a direction, not a number. Note which way crude and each product moved, and how far that is from the published consensus for Wednesday. Do not carry the API's levels into any calculation; they will not match the EIA's levels even when the changes agree.
• Wednesday 10:30: judge the EIA against consensus, not against the API. The price reaction is driven by actual minus consensus. An EIA draw smaller than the API preview is not bearish unless it is also smaller than the market expected.
• Where they disagree, slow down. A product where the two surveys flip sign, like distillates in October 2026, is a product where the week's data is genuinely uncertain. The honest read is the range between the two prints, and the four week average, not either single figure.
• For anything kept, keep the EIA series. Histories, averages, days of supply, and seasonal comparisons must be built from one consistent survey. The EIA series is the one that is public, benchmarked to monthly data, and archived, which is why the data on our analysis page and in our guide to reading the weekly petroleum report is EIA data throughout.

6. Mistakes the two-report system invites

• Treating the API bulletin as a leak of the EIA report. It is a separate survey of the same respondents, published earlier by design. Nothing in it comes from the EIA's compiled data.
• Assuming one of them must be wrong when they differ. Both are estimates covering roughly 90 percent of the industry. A gap of one to two million barrels on a weekly crude change is well inside the normal distance between the two tallies; the October 2026 distillate flip is the tail case, not a scandal.
• Comparing an API change to an EIA level. Headlines report changes; databases store levels. Mixing the API's change with the EIA's level produces stock figures that exist in neither survey.
• Reading the API as the consensus. The API figure is one survey's estimate, published before the official one. Consensus is the analyst survey expectation for the EIA print. The two are different numbers with different jobs.
• Ignoring the products. Crude gets the headline, but the recurring disagreements live in gasoline and distillates, where the pools are smaller and regional coverage differences bite.

7. Frequently asked questions

Which report is the official one, API or EIA?

The EIA report. The Weekly Petroleum Status Report is published by the US Energy Information Administration, the statistical agency of the Department of Energy, from a mandatory survey. The API Weekly Statistical Bulletin is a private industry survey published by the American Petroleum Institute, a trade association. The market treats the EIA figures as the benchmark and the API figures as an early preview of them.

Why do the API and EIA numbers differ if they cover the same week?

They are separate tallies. The API collects copies of the same survey forms companies submit to the EIA, on the same schedule, but participation in the API survey is voluntary, response timing and coverage differ at the margin, and each organization estimates the part of the industry it does not hear from. The API itself states that both surveys cover roughly 90 percent of the industry and publish estimates. Two estimates of the same week rarely match to the barrel, and on individual products they can disagree on direction.

Does the API see the EIA data before it is published?

No. The API does not receive the EIA's compiled report. By the API's own account, it collects an exact copy of the data that companies submit to the EIA, using the same weekly survey forms and the same collection schedule and deadline. Respondents report to both. The API simply publishes its tally first, on Tuesday afternoon instead of Wednesday morning.

Which report moves oil prices more?

The EIA report, because it is the official benchmark: a mandatory survey, the full detail the market models (production, product supplied, district stocks, Cushing, the Strategic Petroleum Reserve), and a free public release at a fixed time in the middle of the trading morning. The API bulletin moves prices on Tuesday evening as a directional signal, and part of that move is routinely confirmed or reversed when the EIA prints.

How often do API and EIA disagree?

On the headline crude figure the two usually point the same way, with different sizes. On individual products, direction disagreements are a recurring feature. In the week ending October 16, 2026, the API reported a distillate draw of 2.6 million barrels on Tuesday, and the EIA reported a distillate build of 1.675 million barrels the next morning: same week, same product, opposite signs, a gap of about 4.3 million barrels between the two prints.

Is the API report free?

The full Weekly Statistical Bulletin is a subscription product, distributed by the API and through data vendors. Its headline stock changes, however, are reported by market news outlets within minutes of the Tuesday release, so the figures that move prices are widely visible even though the complete bulletin is not.

8. Related reading

• EIA Report Schedule, Explained - when both reports, the gas storage report, and the rig count actually come out, including holiday shifts.
• How to Read the EIA Weekly Petroleum Status Report - the Wednesday benchmark, table by table, with a worked reading.
• US Crude Oil Inventory History - the EIA stock series in long context: records, the 2020 spike, and the SPR era.
• EIA Crude Oil Inventory and Weekly Petroleum Status Report - the archived weekly EIA data behind both reports.
• How to Read the EIA Weekly Natural Gas Storage Report - the Thursday release that completes the weekly data cycle.

Data and sources: American Petroleum Institute, Weekly Statistical Bulletin frequently asked questions, read October 21, 2026 (publication schedule; survey of US refiners, bulk storage and blending terminals, pipeline companies, and importers; an exact copy of the data submitted to the EIA, the same EIA weekly survey forms, and the EIA collection schedule and deadline; coverage of crude oil, motor gasoline, kerosene jet fuel, distillate fuel oil, and residual fuel oil; neither the API nor the EIA collects 100 percent of the data, both cover roughly 90 percent of the industry, and both publish estimates). U.S. Energy Information Administration, Weekly Petroleum Status Report and its release schedule page, read October 21, 2026 (standard release Wednesday 10:30 a.m. eastern; holiday exceptions). Market coverage of the October 20, 2026 API bulletin (crude -4.93 million barrels, gasoline -2.0 million, distillates -2.6 million) and of the October 21, 2026 EIA report for the week ending October 16, 2026 (crude -3.060 million against consensus of about -0.82 million; gasoline -2.952 million; distillates +1.675 million against consensus of about -1.162 million), as reported by market news outlets on those dates and read October 21, 2026. All other figures are as published by the sources named, for the periods stated.