Since the fuel measures package took effect on April 1, 2026, profit margins for both E5 and E10 gasoline in Germany have risen by about six cents per liter. The effect on diesel prices, however, remains unclear—at least in the short term—as international diesel prices have been highly volatile since the start of the war. Smaller chains and independent providers, in particular, have raised their profit margins more sharply than large gas station chains. Furthermore, the magnitude of the effect varies considerably within Germany. This is shown for the first time by a joint study by ZEW Mannheim and the Düsseldorf Institute for Competition Economics (DICE). The researchers analyzed data from approximately 15,000 gas stations over a two-week period before and after the new fuel price regulation took effect.
“The package of measures has not yet led to a reduction in price levels. Profit margins rose significantly, particularly for gasoline,” emphasizes Leona Jung, author of the study from DICE.
Leonard Gregor, co-author from DICE, adds: “On the one hand, the daily cycle, which was previously characterized by seven to eight price spikes, has been reduced to a single, predictable midday increase, making favorable time windows easier to identify. On the other hand, higher prices between midday and early evening must be accepted.”
Price predicability has consequences
The results suggest that the predictability of price adjustments indirectly leads to higher average prices. Prices are systematically raised from lunchtime through the evening, while prices in the morning tend to fall below the daily average. Prior to this, consumers had numerous opportunities throughout the day to fill up at lower prices.
Profit margins are rising
To calculate profit margins, the researchers compared fuel prices—excluding taxes and fees—with wholesale prices from the Amsterdam-Rotterdam-Antwerp trading region, known as the “ARA price.”
“While profit margins for gasoline have risen by an average of about six cents per liter since the fuel price regulation took effect, margins for diesel fluctuated significantly during the observation period. Diesel prices rose sharply even before the regulation took effect during the Iran conflict, while gasoline prices reacted with a delay. Due to the short observation period, the increase in diesel margins cannot be reliably quantified,” says Jacob Schildknecht, co-author of the study from the ZEW Research Department “Digital Economy.”
Regional and structural differences
Both region and the size of the gas station chain significantly influence the magnitude of the effect. Smaller chains and independent operators see the largest increases in margins, while the impact is more moderate for medium-sized chains and smallest for large chains.
“This difference shows that the reform does not have a uniform effect, but rather depends heavily on market structure and the intensity of competition. The results suggest that larger companies, in particular, are increasing their margins less sharply, as they, being dominant market players, are more likely to fear antitrust scrutiny,” said Prof. Dr. Justus Haucap, co-author of the study and director of DICE.
In southern Germany, margins have risen particularly sharply—by up to an additional 1.2 cents per liter of gasoline and 2.4 cents per liter of diesel.
“The higher average per capita income in the south could foster a greater willingness to pay and thus larger margin adjustments. Furthermore, regional differences in supply chains and crude oil procurement can lead to cost differences that further amplify regional variations in price reactions,” the researchers note.