U.S. Weekly Fuel Prices

Seasonality, Grade Differences, and the Diesel Premium

Team Trusting Kiwi — Amanda Johnson, Maria Persaud Fernandez, Simah Sahnosh

2026-03-05

Introduction

Source: U.S. EIA via TidyTuesday

Key variables:

  • fuel
  • grade
  • formulation
  • price

Objectives: Visualize & Interpret

  1. How do prices vary by season across fuel type and gasoline grade?

  2. How does the diesel premium evolve over time, and how does it relate to price volatility?

How Do Fuel Prices Change Across Seasons?

Outcomes

  • Gasoline rises sharply in summer (travel demand, higher-cost blends)
  • Diesel changes gradually (industrial and freight demand)
  • Seasonality affects each fuel type differently.

Do All Gasoline Grades Behave the Same?

Outcomes

  • Prices increase across all grades in summer
  • Premium gasoline remains highest in every season
  • Seasonal demand changes price levels,not relative differences

How does the size of the diesel premium change over time?

  • Diesel premium has increased over time.

  • High volatility –> spikes in the diesel premium.

  • Larger premiums –> years with economic instability.

Does Diesel Amplify Gasoline Volatility?

Outcomes

  • Points above the dashed line = diesel more volatile than gasoline
  • Diesel premium widens most when markets are already stressed, compounding costs for freight-dependent industries