What is the best octane for a Chevy Camaro with 305 engine?

The best octane for a Chevy Camaro with a 305 engine depends on what year the Camaro is and whether the engine has been modified. The owner's manual for that specific year and model will specify the recommended octane rating. Generally, a stock 305 engine will run fine on regular unleaded (87 octane).

However:

* Higher octane (89 or 91) might offer slightly better performance or smoothness if the engine is modified (e.g., higher compression ratio, performance upgrades).

* Using a higher octane than recommended won't harm the engine, it'll just be unnecessary expense.

* Using a lower octane than recommended could lead to knocking (pinging) or detonation, which can damage the engine over time. This is more likely in hotter climates or under heavy load.

To find the definitive answer: Consult the owner's manual for your specific Camaro's year and model. This will be the most reliable source of information.