Comparative Study and Testing of Energy Use Rates and Greenhouse Gas emissions Rates of a Diesel 2012 Volkswagen Golf TDI and Electric 2023 Hyundai Ioniq 5Phillips, Kurt carbon dioxideemissionsdieselelectric vehiclefugitive methane emissionsnatural gasenergy efficiencypassenger vehicleenergy use rateEnergy EngineeringB SVehicle emissions data is used to quantify and assess the contribution of automobile transportation to air pollution and climate change. This information is also used to ensure compliance with established federal regulations, such as the Clean Air Act of 1963 and major provisions of 1970, 1977, and 1990. The goal of this work is to compare the overall driving energy use rates and greenhouse gas emissions between a diesel passenger vehicle (2012 Volkswagen Golf TDI) to a similar, modern EV (2023 Hyundai Ioniq 5) that is powered using natural gas electricity generation. Specific objectives of the work include determining relevant emissions and energy rates of an automobile while driving and estimating fugitive greenhouse gas emissions from natural gas transport and use. In December 2025, experimentation was performed using the Volkswagen Golf and the Hyundai Ioniq in Clarksburg, MD to determine respective energy use rates when driving. Vehicles were driven on both city and highway circuits (by the same driver) to determine appropriate disparities. Energy use rates were then used in conjunction with other emissions outlets (such as fuel transport) to estimate total emissions rates. Total diesel and EV vehicle energy rates and greenhouse gas emissions were quantified and normalized to an equivalent rate of carbon dioxide emissions. The results are as follows: • Diesel city energy use rate of 0.74 mi/kWh (27.2 MPG); emissions rate of 411 g CO2/mi. • Diesel highway energy use rate of 1.12 mi/kWh (41.4 MPG); emissions rate of 270 g CO2/mi. • EVcity energy use rate of 4.11 mi/kWh; emissions rate of 89 g CO2/mi. • EVhighway energy use rate of 3.43 mi/kWh; emissions rate of 107 g CO2/mi. EVs that use electricity from natural gas plants have considerably higher driving effi ciencies and lower greenhouse gas emissions rates than similar diesel passenger vehicles. Emissions rates of EVs within this criterion are reduced approximately 2.5 to 4.6 times that of a similar diesel passenger vehicle. From experimentation results, EVs powered by natural gas electricity generation have considerable efficiency and GHG emissions advantages over a similar diesel passenger vehicle.Dr. Ashish Ranjan Kumar, Thesis SupervisorJonathan P Mathews, Thesis Honors Advisoropen_access2026-04-21T14:16:08Zhttps://honors.libraries.psu.edu/catalog/10140kzp5633