EIA Gasoline Stocks Change

It has no standalone release and equals the week over week Difference in Total Motor Gasoline stocks in Table 5. The U.S. Energy Information Administration (EIA) compiles it in the Weekly Petroleum Status Report (WPSR) in million barrels. It rests on 7 weekly surveys of the primary supply chain, with a sample covering about 90% of volumes. It runs as a long weekly series and covers stocks at refineries, bulk terminals and pipelines only.

It excludes secondary stocks at small bulk plants served by truck or tank car, retail outlets and consumer tanks. It also excludes the Northeast reserves, which sit outside commercial gasoline statistics. Fuel ethanol appears in the same table but never counts inside Total Motor Gasoline. Reported demand is only implied disappearance, so a build never directly measures demand.

Each cycle covers one full week from morning to morning, and respondents file early in the following week. Summary tables and highlights come out first, and the full report with This Week in Petroleum (TWIP) follows later on the same release day. Holiday weeks can shift the schedule. Each release sits inside the full report with balance, stocks, trade and price tables plus a highlights narrative.

Revisions appear only when they would change the reading of fuel supply, and late reports feed later estimates instead. Late or corrected reports otherwise enter editing and imputation for later periods. Analysts watch the release closely on publication day, since surprises can move spot and futures prices, but the publisher states no buy or sell trigger.

The headline moves with its fuel parts and with regional shifts, so a build in one part can offset a draw in another.

• Finished Motor Gasoline: fuel blended for spark ignition engines, split into reformulated and conventional grades, and a small share of stocks.
• Conventional: the non-reformulated part of finished stocks, reported for each district.
• Reformulated: the reformulated part of finished stocks, reported for each district.
• Blending Components: naphthas mixed into finished gasoline, including RBOB, but excluding oxygenates, butane and pentanes plus, and the bulk of stocks.
• Fuel Ethanol: a blending alcohol shown in the same table but never counted in Total Motor Gasoline.
• Regional split: stocks break into 5 districts covering the East Coast, Midwest, Gulf Coast, Rocky Mountain and West Coast.

Readers often compare the level with the 5 year average for context, since the publisher frames stocks as above or below that average.

1. Impute missing reports: gaps are filled by exponential smoothing, which blends a past report with a prior estimate. The formula is Yt = α * yt + (1 - α) * Yt-1, with α set by survey and product. Imputed values enter estimation like reported values.
2. Expand to the full set: weekly sums scale by a ratio from the reference month. Weekly sums scale by all firm stocks over same firm stocks, computed separately for refineries, terminals and pipelines. Suppose a stratum books 4400 thousand barrels for the week, with same firm reference month stocks of 45000 and all firm stocks of 50000. The expanded stratum is 4888.9 thousand barrels, and the total sums across types.
3. Convert and difference: levels collected in thousand barrels publish in million barrels, and differences come from unrounded data. The change equals this week minus the previous week, so a negative value means stocks fell. Totals can differ from summed parts through independent rounding.
4. No seasonal adjustment: the method applies no seasonal adjustment and no fixed weights. The only weight is the expansion ratio, adjusted solely for unusual events.