The Audi A4 45 TFSI Quattro S Line, with its powerful 265-hp turbocharged engine, undergoes a cost analysis to determine its real-world fuel consumption and overall running expenses. This performance sedan delivers a balanced mix of speed and comfort, but how does it fare in everyday use? Our test revealed an average fuel consumption of 8.2 liters per 100 kilometers, slightly higher than the WLTP-rated figure. This translates to fuel costs of 14.10 euros per 100 kilometers. On an eco-friendly driving route, the A4 showed impressive fuel economy with a consumption of 5.9 liters per 100 kilometers, resulting in fuel costs of 10.15 euros for the same distance. Even when driven aggressively, the A4’s fuel consumption remained within reasonable limits at 9.8 liters per 100 kilometers, leading to fuel costs of 16.86 euros per 100 kilometers. In addition to fuel costs, the Audi A4 incurs annual taxes of 223 euros, while insurance premiums for liability, partial coverage, and full coverage come to 284, 350, and 736 euros, respectively. The monthly running costs for the Audi A4 are estimated at 301 euros for a yearly mileage of 15,000 kilometers and rise to 546 euros when the mileage doubles. This cost analysis highlights the real-world performance and economic considerations of owning the Audi A4 45 TFSI Quattro S Line.