Why Do Fighter Jets Use Less Refined Fuel Than Cars?

The question asks why fighter jets use less refined fuel than cars. However, based on the evidence provided, it seems there might be a misunderstanding in the comparison. Fighter jets and cars use different types of fuels due to their specific requirements for performance, efficiency, and environmental considerations.

1. Fuel Type: Fighter jets primarily use jet fuel, which is highly refined kerosene-based liquid designed specifically for jet and turbine engines. This fuel is optimized for high-performance applications where high energy density and low viscosity are crucial. In contrast, automotive gasoline (avgas) contains tetra-ethyl lead additives for lubrication and to prevent knocking, with higher octane ratings compared to standard automotive gasoline.

2. Performance Requirements: Aircraft engines operate at much higher compression ratios and temperatures than road vehicles. Therefore, they require fuels that can withstand these conditions without detonating prematurely. Jet fuel has specific properties such as high flashpoints and cetane ratings that ensure optimal engine performance under these extreme conditions.

3. Environmental Considerations: While both jet fuel and automotive gasoline produce similar amounts of CO2 per gallon when burned, there are ongoing efforts to develop sustainable aviation fuels (SAF) derived from biomass or other renewable sources to reduce carbon emissions. These SAFs contain more oxygenates and fewer impurities than traditional fossil-based fuels.

4. Efficiency and Emissions: Sustainable aviation fuels may potentially reduce greenhouse gas emissions significantly. For instance, the UK plans to replace up to 30 percent of fighter jet fuel with biomass by 2050 as part of its carbon neutrality goals.

In summary, fighter jets use highly specialized fuels like jet fuel due to their unique performance requirements and the need for high energy density and low viscosity. While automotive gasoline also undergoes refining processes, its composition and additives differ significantly to meet the specific needs of internal combustion engines in vehicles.