SEE 477/870: Sustainable Vehicle Systems - Transportation, Energy Use, Emissions, and Regulation

Comprehensive vocabulary flashcards covering transportation modes, vehicle classifications, powertrain architectures, life cycle and well-to-wheel analysis, environmental emissions, and North American and European emissions regulatory standards.

EPA Light-Duty Vehicle Classification Tree

The regulatory taxonomy dividing light-duty vehicles into Car (subdivided into Sedan/Wagon and Car SUV) and Truck (subdivided into Truck SUV, Minivan/Van, and Pickup).

Gross Vehicle Weight Rating (GVWR)

The maximum permissible operating weight of a vehicle specified by the manufacturer, encompassing the unladen vehicle mass plus cargo, fluids, and passengers.

Gross Combined Vehicle Weight (GCVW)

The maximum allowed combined operating rating for a tractor and trailer combination, typically capped at $80{,}000\,\text{lbs}$ on standard highways and up to $140{,}000\,\text{lbs}$ for B-train configurations.

Cubed Out

A shipping constraint in which a transport vehicle reaches its full internal volumetric storage capacity before reaching its legal gross vehicle weight limit.

Grossed Out (Weighted Out)

A shipping constraint in which a transport vehicle reaches its legal gross operating weight limit before filling its available volumetric cargo space.

Spark Ignition (SI) Engine

An internal combustion engine that operates using a premixed air-fuel charge (such as gasoline/petrol) that is ignited inside the combustion chamber by an electrical discharge from a spark plug.

Compression Ignition (CI) Engine

An internal combustion engine that injects non-premixed fuel (such as diesel) directly into cylinders where the air charge is heated purely by mechanical compression, initiating auto-ignition.

Battery Electric Vehicle (BEV)

An all-electric vehicle that eliminates the internal combustion engine and mechanical power coupling, using onboard high-voltage lithium-ion batteries and an inverter to drive an electric motor while recovering kinetic energy through regenerative braking.

Fuel Cell Electric Vehicle (FCEV)

An electric propulsion vehicle that utilizes an on-board electrochemical cell (typically a proton-exchange membrane fuelled with hydrogen) to combine hydrogen and oxygen into electricity, water, and heat.

Parallel Hybrid Electric Vehicle Architecture

A hybrid vehicle drivetrain configuration that couples both an internal combustion engine and an electric motor to the driveline through a mechanical coupling mechanism, allowing either or both to supply tractive power.

Plug-In Hybrid Electric Vehicle (PHEV)

A hybrid vehicle integrating an internal combustion engine with an electric motor and a traction battery that can be plugged into an external electrical grid source to provide extended all-electric driving range.

Life Cycle Assessment (LCA) vs. Well-to-Wheel (WTW) Boundary

The structural distinction between an in-service fuel-cycle assessment (WTW: feedstock production to vehicle fuel operation) and a complete cradle-to-grave analysis (LCA: incorporating vehicle material extraction, plant fabrication, distribution, maintenance, and vehicle disposal).

Well-to-Wheel (WTW) Analysis

A specialized fuel-cycle assessment framework that accounts for total energy consumption and greenhouse gas emissions from the initial raw energy resource extraction through fuel transformation, delivery, and eventual in-vehicle propulsion.

Well-to-Tank (WTT)

The upstream segment of a fuel-cycle analysis encompassing primary energy feedstock harvesting, transport, refining, secondary processing, distribution, and storage dispensing into a vehicle tank or battery.

Tank-to-Wheel (TTW)

The operational downstream segment of a fuel-cycle analysis that quantifies how efficiently energy stored onboard a vehicle is converted into useful motive mechanical work at the wheels.

GREET

The Greenhouse gases, Regulated Emissions, and Energy use in Technologies lifecycle modeling software developed by Argonne National Laboratory in the United States.

GHGenius

A lifecycle emissions modeling software tool developed by Natural Resources Canada (NRCan) to quantify greenhouse gas emissions for contemporary and alternative transportation fuels.

Net Greenhouse Gas Intensity ($GHG_{\text{net}}$) Equation

The formula used to calculate net emissions per unit of fuel delivered: $GHG_{\text{net}} = \frac{\sum_{\text{step } j} \sum_{\text{species } i} (m_{i,j} \times GWP_i)}{E_{\text{delivered}}}$, where $m_{i,j}$ is emitted mass, $GWP_i$ is Global Warming Potential, and $E_{\text{delivered}}$ is net delivered energy.

Carbon Intensity (CI)

A standardized metric representing lifecycle greenhouse gas emissions per unit of energy delivered, expressed in $\text{gCO}_2\text{e/MJ}$ under regulations such as California's Low Carbon Fuel Standard (LCFS).

Lower Heating Value (LHV)

The amount of combustion heat released by fully burning a unit mass of fuel when water remains in vapor form; values include $120\,\text{MJ/kg}$ for hydrogen, $50\,\text{MJ/kg}$ for methane, and $\approx 43.1\,\text{MJ/kg}$ for gasoline.

Corporate Average Fuel Economy (CAFE)

Federal standards established by the United States National Highway Traffic Safety Administration (NHTSA) regulating sales-weighted average fleet fuel economy for light-duty vehicles.

Vehicle Footprint

A geometric attribute determined by multiplying a vehicle's average track width by its wheelbase ($\text{track width} \times \text{wheelbase}$), used by CAFE and EPA rules to set attribute-based $\text{CO}_2$ and fuel economy compliance targets.

FTP-75 Drive Cycle Profile

A standardized transient chassis dynamometer cycle divided into cold start ($0 - 505\,\text{s}$), stabilized ($505 - 1372\,\text{s}$), hot soak ($1372 - 1972\,\text{s}$), and hot start ($1972 - 2477\,\text{s}$) phases.

Worldwide Harmonized Light Vehicles Test Cycle (WLTC)

A global chassis dynamometer test cycle used primarily in European certification that features acceleration dynamics similar to the FTP-75 but incorporates significantly higher maximum vehicle velocities.

Real Driving Emissions (RDE)

An on-road vehicle testing requirement implemented in Europe under Euro 6d that evaluates tailpipe pollutants ($\text{NO}_x$ and particle number) under authentic driving conditions across urban, rural, and motorway legs.

Conformity Factor (CF)

A statutory multiplier (presently $1.43$ in European RDE regulations) applied to baseline laboratory emission thresholds to define the legal upper ceiling for real-world on-road PEMS testing.

Portable Emissions Measurement System (PEMS)

An integrated onboard analytical gas and particle analyzer package attached to a test vehicle to directly sample and record real-world tailpipe emissions while driving on public roadways.

Not-to-Exceed (NTE) Limit

A heavy-duty diesel engine regulatory requirement mandating that emissions must not exceed $1.5 \times$ the certified brake-specific emissions standard within a designated operational speed-torque zone.

VECTO

The Vehicle Energy Consumption Calculation Tool, an official European Union simulation program used to determine fuel consumption and fleet-average $\text{CO}_2$ emissions for heavy-duty commercial trucks.

Supercredit

A regulatory multiplier incentive under heavy-duty greenhouse gas regulations that allows a manufacturer to count an individual zero-emission vehicle as two vehicles when computing compliance with fleet-wide $\text{CO}_2$ targets.

Criteria Air Contaminants (CAC)

A regulatory group of hazardous air pollutants that directly impact human health and the environment, consisting of sulphur oxides ($\text{SO}_x$), nitrogen oxides ($\text{NO}_x$), particulate matter ($\text{PM}$), volatile organic compounds ($\text{VOCs}$), and carbon monoxide ($\text{CO}$).

Secondary Air Pollutants

Atmospheric pollutants formed when primary emissions undergo chemical reactions in the atmosphere; examples include tropospheric ozone ($\text{O}_3$), peroxyacyl nitrates (PAN), and secondary particulate sulphates/nitrates.

Photochemical Smog Diurnal Concentration Profile

The characteristic daily concentration curve in which morning commute emissions of $\text{NO}$ and $\text{VOCs}$ are oxidized by sunlight into $\text{NO}_2$, driving subsequent afternoon reactions that produce peak concentrations of ozone ($\text{O}_3$) and photochemical oxidants.

Respiratory Tract Particulate Matter Deposition

The size-selective physical deposition of airborne particles within the human respiratory tract: particles $> 10\,\mu\text{m}$ deposit in the nose and throat, $2.5 - 10\,\mu\text{m}$ in bronchial tubes, $1 - 2.5\,\mu\text{m}$ in bronchioles, $0.1 - 1\,\mu\text{m}$ in alveoli, and $< 0.1\,\mu\text{m}$ penetrate into the bloodstream.

Fine Particulate Matter (PM2.5)

Airborne solid and liquid particles possessing an aerodynamic diameter of $2.5\,\mu\text{m}$ or smaller that penetrate deep into the lungs; the WHO recommends an annual mean limit of $10\,\mu\text{g/m}^3$, where each $2.5\,\mu\text{g/m}^3$ reduction lowers mortality by $\approx 3.5\%$.

Global Warming Potential (GWP)

A relative scale indexing the radiative heat absorption of a gas over a specific timeframe (typically $100\,\text{years}$) relative to $\text{CO}_2$ ($\text{GWP} = 1$), yielding values of $28 - 36$ for $\text{CH}_4$, $265 - 298$ for $\text{N}_2\text{O}$, and $23{,}500$ for $\text{SF}_6$.