Why does fuel consumption increase after changing the mid and rear exhaust sections?
2 Answers
Because the backpressure level of the exhaust pipe affects the exhaust velocity. Whether the speed is fast or slow, it will influence the combustion efficiency at different RPM ranges. Excessively fast exhaust flow may cause unburned gases to be expelled, while overly slow exhaust flow increases cylinder temperature and reduces oxygen content, leading to decreased combustion efficiency. The ultimate result in both cases is increased fuel consumption and reduced power output. Here are additional details: 1. During modification: When modifying the exhaust system, it's necessary to select components based on the engine displacement and vehicle model, striving for optimal compatibility with the engine. 2. Automotive exhaust system: The automotive exhaust system refers to the assembly that collects and discharges waste gases, typically consisting of exhaust manifold, exhaust pipe, catalytic converter, exhaust temperature sensor, muffler, and tailpipe.
Increased fuel consumption after replacing the mid-to-rear exhaust section is primarily due to the modification altering the exhaust system's backpressure. Excessively low exhaust backpressure makes engine exhaust too smooth, causing the ECU to struggle with fuel injection control, leading to lower combustion efficiency and increased gasoline consumption. Also check for installation issues like loose connections causing leaks - exhaust leaks can trigger false O2 sensor readings, resulting in richer air-fuel mixtures and higher fuel consumption. Additionally, louder exhaust notes tend to excite drivers, prompting more aggressive acceleration that naturally spikes fuel usage. My advice: don't just chase sound thrills - consult professional tuners before installation to ensure compatibility with OEM systems, with ECU recalibration if necessary for performance balance. If fuel economy issues emerge post-installation, promptly inspect sealing and sensors to prevent long-term engine damage.
