What happens to a vehicle that is not designed for high alcohol fuel?

Vehicles not designed for high alcohol fuel, such as those containing a significant percentage of ethanol, can experience considerable damage to their fuel systems. Ethanol is more corrosive than gasoline and can degrade certain materials commonly used in fuel system components, such as gaskets, seals, and fuel lines. This degradation can lead to leaks and failures that may compromise the overall functionality of the vehicle.

Additionally, vehicles not built to withstand the effects of high alcohol fuel might face issues like fuel dilution, poor combustion characteristics, and potential engine performance problems stemming from incorrect air-fuel ratios. These effects are pronounced if the vehicle's components are not compatible with the chemical properties of the ethanol, underscoring the importance of using the appropriate fuel for vehicle specifications.

The other options present possibilities that are generally not true for vehicles not designed for high alcohol fuels. For example, increased engine performance or better fuel efficiency would typically result from fuels that are designed for specific engine calibrations and materials. Improvement in emissions is also unlikely, as improper fuel can lead to incomplete combustion and potentially increase harmful emissions instead.