The adoption rate of zero tailpipe emission road vehicles (ZEVs) is insufficient in Sweden and the EU for the 2030 greenhouse gas (GHG) reduction targets to be met. The average life length of internal combustion engines vehicles (ICEVs) is 10-17 years and there is a higher export rate of used EVs than ICEVs, two factors that essentially lock in a large portion of emissions for nearly two decades. This pre-study explores the potentials and challenges of retrofitting of ICEVs with electric powertrains (E-retrofit), a complementary path to fleet decarbonization. It focuses on determining vehicle types and applications where conversion is cost-effective, environmentally beneficial, and technically feasible. Today, E-retrofitting is a niche industry, foremost focused on special-purpose vehicles with costly bodywork or equipment, such as off-road machinery, city buses, fire trucks, and last-mile delivery vans. Classic cars with high affection values that have been e-retrofitted illustrate that E-retrofit is technically feasible, though these enthusiast conversions are typically performed at high economic cost per vehicle and with negligible impact on overall fleet emissions. The E-retrofit process includes selecting a donor vehicle, calculating energy needs, assessing total cost of ownership, designing and installing an electric drivetrain, and re-certifying the vehicle for road use. Various stakeholders are involved in this process, including E-retrofit kit developers who can develop and sell generic or vehicle model specific solutions. However, there are significant technical and cost barriers, including the integration of proprietary OEM vehicle control units (VCUs), often requiring manual adjustments and software modifications. Existing ICEV architectures also complicate battery placement, potentially affecting range, weight distribution, and needs for reinforcements, making re- certification and homologation more complex.