| Answer | Crossword Clue |
|---|---|
| RRR | Sound of a recalcitrant engine |
| PUTPUT | Sound of a small engine. |
| PURR | Sound of a sleek engine |
| PURR | Sound of a quiet engine. |
| PURR | Sound of a tuned engine |
| SPUTTER | Sound of a dying engine |
| PURR | Sound of a happy engine |
| PURR | Sound of a finely tuned engine |
| PURR | Sound of a well-tuned engine. |
| PURR | Sound of a cat or engine |
| PURR | Sound of a fine-tuned engine |
| HUM | Sound of a well-tuned engine |
| PURR | Sound of a well-tuned engine |
