| Answer | Crossword Clue |
|---|---|
| STP | Popular fuel additive |
| STP | Popular fuel additive brand |
| DEICER | Fuel additive |
| GASTAX | Fuel additive? |
| STP | Fuel additive |
| ETHANOL | Fuel additive |
| STP | Fuel additive brand |
| DRYGAS | Fuel additive, perhaps |
| ETHYL | Car fuel additive |
| DRYGAS | Fuel line additive |
| STP | Racecar fuel additive |
| TRIPTANE | Plane-fuel additive |
| STP | Fuel additive letters |
| STP | Motor fuel additive |
| AMYL | ... nitrate (diesel fuel additive) |
| STP | Fuel additive on the NASCAR circuit |
| ferrocene | an orange crystalline compound used as a fuel additive |
| ferrocenes | FERROCENE, an orange crystalline compound used as a fuel additive |
