Final answer:
Using fuel with an octane rating higher than needed for a vehicle does not improve performance or efficiency and is not cost-effective. Premature combustion issues arise with lower octane fuels, not higher ones. High-performance engines benefit from high-octane fuels to avoid knocking and pinging.
Step-by-step explanation:
The continuous use of fuel with an octane rating higher than what is specified for a particular engine may not necessarily result in immediate damage, but it does not offer any benefit and can be a needless expense. The octane rating of gasoline is a measure of its ability to resist knocking and pinging during combustion, which are signs of premature ignition of the fuel-air mixture. The octane rating system was established with n-heptane (rated 0) and isooctane (rated 100) as references. Fuels with a higher octane rating than 100 have been developed, which are better than pure isooctane, and octane enhancers like ethanol are being used more frequently due to environmental and health concerns over previous additives like MTBE and lead compounds.
Using a higher octane fuel than required does not increase engine performance or efficiency for engines not designed to take advantage of such fuels. Premature combustion primarily occurs when the octane rating is too low for the engine, not too high. Vehicles equipped to handle high-octane fuels are typically high-performance or turbocharged engines which can actually benefit from these fuels to prevent knocking and pinging effects when operated at high speeds or loads.