As the 2026 school year begins, the price of diesel is averaging around 2.25 euros per liter, a significant increase from earlier in the year. This rise in fuel prices has been driven by ongoing geopolitical tensions in the Middle East, which have disrupted oil traffic through the Strait of Hormuz—a key global shipping route for petroleum. These disruptions have led to higher fuel costs, prompting some drivers to seek alternative, more affordable ways to power their vehicles. In response to these rising costs, some motorists, like Marie and Lucas (names have been changed), have turned to unconventional methods to cut their fuel expenses. Marie, who has been using cooking oil as fuel for 15 years, explains that she collects used oil from restaurants, food trucks, and flea market vendors. This oil, once filtered and decanted, is stored at home in containers ranging from 25 to 50 liters. While the process requires careful handling and is not as simple as filling a tank with gasoline, Marie finds the effort worthwhile. "I recover large containers of 25 liters. You have to be methodical, it's not water, you can put it everywhere," she notes. The oil also brings a unique aroma to her car—sometimes the scent of fried food or spring rolls—though she jokes that it’s a small price to pay for savings. Lucas, on the other hand, uses a different approach. Instead of collecting used oil, he buys cheap rapeseed oil from stores at around 1.45 euros per liter. He mixes it with a small amount of diesel to power his car, saving up to 70 cents per liter. "With the increase in prices on all sides, we are forced to find tricks to pay less and make savings," he says. However, he acknowledges the legal risks. "I know it's illegal, but there's more benefit than risk," he admits, noting that the risk of being stopped by authorities is low, as such checks are rare. While both Marie and Lucas have found ways to reduce their fuel costs, they also acknowledge the limitations and challenges of using cooking oil as fuel. Marie explains that only older vehicles, like her Mercedes and her husband’s Peugeot, are suitable for this method, as newer cars have complex electronics that can be damaged by such fuel. In winter, the oil tends to freeze, requiring additional measures like heaters to start the car. Lucas also warns that the oil can clog injectors, requiring more frequent maintenance. Despite these challenges, both drivers believe the environmental benefits—reducing reliance on fossil fuels—make the effort worthwhile. While these practices offer economic and ecological advantages, they remain on the fringes of legality and practicality for most drivers.