3. A chemical element commonly used in engine oils for cleaning and dispersing contaminants. 

7. A flexible tube used to carry liquids or gases in various systems.

9. A famous figure in the oil industry, known for making the first oil strike.

11. A common substance that is filtered in engines to ensure optimal performance.

12. A method used to extract oil and gas by injecting high-pressure fluid into rock.

14. The rotational force that causes an object to rotate around an axis.

15. The amount of loose play or excess movement in mechanical systems.

17. A gear system that allows wheels to rotate at different speeds.

19. A component used to prevent the leakage of fluids in machines or engines.

20. A substance used to reduce friction and wear between moving parts in engines.

23. A central shaft for a rotating wheel or gear, crucial for vehicle movement.

24. A storage container that holds fluids like coolant.

27. A device that detects changes in physical conditions, often used for monitoring.

28. Interlocking mechanical parts that transmit torque and motion in machinery.

1. The forward force produced by engines or turbines to propel an object.

2. The gradual loss of material due to friction or use over time.

4. A substance added to oil to enhance its properties and performance.

5. The presence of this element in engine oils indicates an internal coolant leak.

6. The statistical average of a set of values or measurements to determine rate of wear.

8. A family whose company monopolised the oil industry during its early stages.

10. A component that converts linear motion into rotational motion in an engine.

13. A crude oil derivative collected from the top trays of the fractionating column.

16. The part of an engine where fuel is burned to produce power.

18. A device that removes contaminants from fluids to ensure clean operation.

19. Rotating components that transmit mechanical power within a system.

21. Refers to the measurement of fluid flow or viscosity.

22. The mixture of fuel and air that enters an engine cylinder for combustion.

25. A testing method used to assess varnish formation.

26. A measure of an oil’s alkalinity, indicating its ability to neutralise acids.