The 12 O’Clock Fuel Regulation: 6-Cent Increase in Retail Margins
Research
27.04.2026
Time Series Analysis by ZEW and DICE Shows Development of Pump Prices
Since the package of fuel price relief measures came into force on 1 April 2026, retail margins for both E5 and E10 petrol in Germany have risen by around six cents per litre. The effect on the prices for diesel remains unclear, at least in the short term, because international diesel prices have been highly volatile since the start of the Iran war. Smaller chains and independent suppliers have raised their profit margins more sharply compared to the large petrol station chains, and the strength of the reform’s effect moreover varies considerably within Germany. These are the findings of a study – the first to evaluate the reform – jointly conducted by ZEW Mannheim and the Düsseldorf Institute for Competition Economics (DICE). The researchers analysed data from around 15,000 petrol stations over a two-week period both before and after the new fuel price regulation came into force.
“So far, the relief measures have failed to reduce price levels. Retail margins have risen significantly, especially for petrol,” emphasises Leona Jung, author of the DICE study.
Leonard Gregor, co-author and also from DICE, adds: “On the one hand, the daily cycle, which is characterised by seven to eight price peaks, is reduced to a pattern with a single, predictable peak. This makes it easier to identify time slots when prices are lower. On the other hand, consumers have to accept that prices are higher between noon and early evening.”
The Consequences of Price Predictability
The study findings suggest that the predictability of price adjustments indirectly leads to higher average prices. From noon until the evening, prices are systematically elevated, whilst prices in the morning hours tend to fall below the daily average. Previously, consumers had multiple opportunities to refuel at lower prices throughout the day.
Rising Margins
To calculate margins, the researchers compared retail prices net of taxes and fees with wholesale prices from the European Amsterdam–Rotterdam–Antwerp (ARA) trading region, known as the ‘ARA prices’.
“Retail margins on petrol have risen by an average of around six cents per litre since the fuel price regulation was introduced, but margins for diesel fluctuated significantly during the observation period. Diesel prices had already risen sharply since the beginning of the Iran war, before the introduction of the regulation. Petrol prices, however, were slower to adjust. Due to the short observation period, it is not possible to quantify the rise in diesel margins with any certainty,” says Jacob Schildknecht, co-author of the study from the ZEW Research Unit “Digital Economy”.
Regional and Structural Differences
Region and size of a petrol station chain both significantly influence the strength of the effect. Smaller chains and independent operators are recording the largest increases in margins, whilst the impact is more moderate for medium-sized chains, and lowest for large chains.
“Considering this difference, it is evident that the effect of the reform varies and strongly depends on market structure and intensity of competition. The results suggest that especially larger companies are keeping their margin growth under control – as dominant market players, they are more likely to come under antitrust scrutiny,” says Professor 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 litre of petrol and 2.4 cents per litre of diesel.
“The higher average per capita income in the south may support a greater willingness to pay and thus lead to larger margin adjustments. Furthermore, regional disparities in supply chains and crude oil sourcing may generate cost differences that further amplify regional variations in pricing responses,” the researchers note.
About the Study
The study is based on high-frequency price data from all German petrol stations provided by the Market Transparency Unit for Fuels (MTS-K). Considering a 14-day period window around 1 April 2026, i.e. the day the reform became effective, the researchers analysed around 420,000 observations for E5 petrol and Diesel. The results for E5 are almost identical to those for E10, which is why the researchers focused on one fuel type. To calculate the retail margins, they compared the retail prices with the wholesale prices from the European Amsterdam–Rotterdam–Antwerp trading region (‘ARA prices’).
