Horsepower and Fuel Economy Over Time

This research examines to what extent horsepower predicts fuel economy after controlling for curb weight and engine displacement, and how this relationship has evolved over time. Although higher horsepower generally implies lower fuel economy, the relationship may not be strictly linear. This topic is significant because fuel efficiency affects consumer fuel costs and pollution, while vehicles have become larger and more powerful due to changing consumer preferences and technological developments. Understanding whether technological progress has changed the traditional performance efficiency trade-off is especially relevant in the context of tightening fuel economy standards. Using EPA certification data and manufacturer specifications for gasoline-powered stock vehicles, I will run multiple regression analyses with fuel economy as the dependent variable and horsepower as the key independent variable, controlling for curb weight, engine displacement, cylinder count, model year, and fuel type. I expect to find that the horsepower penalty on fuel economy has diminished over time.