Forecast Signal

Regular Gasoline, Retail: Six-Month Forecast

$4.27 projected by Mar 2027 (−1.9% from $4.35 in Sep 2026), 80% band $3.78 to $4.77. A six-month statistical projection for regular gasoline, retail, shown with a prediction band and historical backtest error.

The six-month projection

  • Projected for Mar 2027: $4.27, −1.9% versus $4.35 in Sep 2026.
  • Prediction band at the six-month horizon: 80% band $3.78 to $4.77.
  • Direction: Within error. The −1.9% move sits inside the 80% band, so the model cannot call its direction.
  • Out-of-sample backtest error (MAPE): 6.5%, one step ahead on months the model had not seen.

Statistical extrapolation, not a market or policy forecast

  • It knows nothing about the next Fed decision, OPEC action, or policy change. Read the prediction band and the backtest error, not just the central line.
  • This series publishes weekly. The model averages those weekly readings into one point per calendar month and forecasts monthly, so it is anchored on September 2026, the most recent COMPLETE month. The newest weekly reading, $4.28 on 2026-10-19, is not in the anchor yet, it belongs to a month that is still filling, and joins the model once that month closes.

How it is built

  • The series is collapsed to one point per month, then projected six months with Holt linear exponential smoothing with a damped trend and no seasonal pattern. The smoothing parameters are grid-searched by walk-forward validation on an early tuning segment, and the reported error is the mean absolute percentage error on a final evaluation segment never used for selection or band calibration. Deterministic: the same data always yields the same forecast.
  • The 80% band is an empirical residual band: at each horizon its width is the 80% quantile of this series' own fixed-parameter walk-forward residuals (13 residuals at the six-month horizon).

Download and query it

  • This forecast, its band, and its backtest are free to download (CC BY 4.0) and available as an open, keyless JSON API and an MCP tool.
  • Source: EIA Gasoline and Diesel Fuel Update, weekly. Underlying series is U.S. government open data, public domain.

Last reviewed 2026-10-06.