Across
1. Clutch-assembly component (8,5)
8. Volatile substance in quick-start fluid
9. Engine-friction reducer
10. Central element in planetary gearset (3,4)
11. The T in dragstrip E.T.
13. Engine design
15. Gasoline-rating term
18. Irksome tire trouble
20. Roller-bearing adjective
23. Affirmative words on cop-car radio (3,4)
24. Wheel-nut adjective, perhaps
25. Service-area features (5,8)
Down
1. Bearing-installation method, sometimes (5,3)
2. Substance blended with gasoline, sometimes
3. Term for unevenness in carburetion
4. Increase a cylinder’s diameter
5. Ubiquitous modern-car material
6. A motor-oil service grade (1,1,1,1,1)
7. Sharp ’08 Ford crossover model
12. One-way-out streets (4,4)
14. Power-boosting gas, briefly
16. Service-station convenience (3,4)
17. In-dash car-tunes source
19. Cylinder-repair sleeve
21. Crankshaft-bearing adjective
22. Roof with removable panels (1,3)