Ingredients of Fuel Economy

A broad overview of passenger car fuel economy is presented. The main components of vehicle power requirement (aerodynamics, rolling resistance, and inertia) are discussed for steady-state and driving cycle conditions. The effects of driveline losses and parasitic losses are mentioned. Fuel effects (alcohols vs hydrocarbons) are discussed along with engine types and differences due to combustion systems.

The total energy required to propel a vehicle is calculated over the Environmental Protection Agency urban/highway driving cycles. The effects of vehicle weight, size, shape, and tire type on vehicle power requirement are presented, and fuel economy trends are predicted. Estimates of the fuel economy of a vehicle with regenerative braking are made.