| Answer | Crossword Clue |
|---|---|
| STP | Gas additive letters |
| STP | Gas-additive letters |
| STP | Gas additive |
| ETHYL | Gas additive |
| ETHANOL | Gas additive |
| STP | Popular gas additive |
| STP | Gas-tank additive |
| STP | Gas additive brand |
| STP | Gas tank additive |
| ODOR | Gas additive, perhaps |
| STP | Gas-line additive |
| EPA | It's phasing out MTBE as a gas additive |
