| Answer | Crossword Clue |
|---|---|
| ETHYL | Anti-knock additive |
| OCTANE | Anti-knock number |
| ETHYL | Anti-knock fluid |
| ETHYL | Anti-knock fluid. |
| ETHYL | Anti-knock fuel |
| OCTANE | Anti-knock stuff |
| OCTANE | Anti-knock measure |
| ETHYL | Old anti-knock fuel |
| OCTANE | Rating in anti-knock gasoline. |
| OCTANES | Anti-knock elements in motor fuel. |
