Why is the Sylphy not suitable for natural gas combustion?
2 Answers
Sylphy cannot use natural gas as fuel because the engine will report an air flow meter fault when burning natural gas. The following are specific details about the air flow meter: 1. Function: The air flow meter measures the volume of fresh air and the intake air temperature entering the engine intake manifold. The ECU uses this information to adjust fuel injection quantity, limit smoke emission, and control the EGR valve opening. 2. Installation position: It is installed on the engine intake pipe, behind the air filter. 3. Working principle: Several electronic components are integrated on a ceramic substrate. During normal engine operation, the diaphragm is first heated. When fresh air flows through the sensor, it carries away some heat. The ECU then controls the Wheatstone bridge on the diaphragm to replenish the heat, causing a change in the electrical signal. When this signal is transmitted to the ECU, the ECU calculates the intake air volume based on this change.
I've been repairing cars for over a decade, and Nissan Sylphy owners often ask if they can run on natural gas. Honestly, it's not a good idea. The factory engine is specifically tuned for gasoline, with fixed compression ratios and valve clearances. Natural gas burns at higher temperatures, which can easily damage valve seals, leading to leaks or power loss. The Sylphy has limited underbody space, and installing a CNG tank requires cutting into the spare tire well—such extensive modifications compromise the car's structural rigidity. If the car encounters bumps or collisions, the risk of tank rupture is significant. I once had a customer whose engine frequently shook and lacked acceleration after conversion; repairs were costly and troublesome. If you truly want to use cleaner fuel, it's better to choose a factory-supported natural gas model, like the modified BYD F3, which is designed for safer and more reliable operation. In short, making unverified modifications poses serious safety risks—it's just not worth the gamble.
