Abstract
Modern engine management compensates for many intake disturbances through closed-loop control, and partial clogging of the air filter leaves fuel consumption of a fuel-injected engine largely unchanged. The intake tract carries a broader range of progressive faults, including boost leaks, turbocharger degradation, fouling of the exhaust gas recirculation valve, coking of the intake manifold, and sensor drift. These faults raise fuel consumption and emissions, and they stay hidden until an onboard diagnostic code appears or a clear power loss develops. This work describes a small-range differential pressure sensor that measures the aerodynamic resistance of the intake path on a continuous basis and reduces that measurement to an Intake Aerodynamic Health Index, the IAHI. The purpose of the index is to enable early detection of intake faults that drive fuel and emission penalties, with filter replacement scheduling treated as a secondary use. A theoretical model built on relations among pressure drop, pumping power, and specific fuel consumption quantifies the direct pumping contribution and shows it to be small. A conditional sensitivity analysis estimates the potential energy and carbon impacts for the subset of vehicles that carry such faults, covering diesel, boosted, fleet, and heavy-duty applications. The sensor architecture, governing equations, modeling assumptions, conditional fleet sensitivity, study limitations, and a planned validation protocol form the body of the contribution. Every percentage stays a modeling assumption, and the index value derives from the resistance signature of an individual vehicle measured against its own healthy reference.