What is the spark plug model for the Classic Focus?
2 Answers
Classic Focus spark plug model is TR6F13. What does a spark plug consist of: A spark plug mainly consists of a terminal nut, insulator, terminal stud, center electrode, side electrode, and shell. What types of spark plugs are there: Main types of spark plugs include: standard spark plugs, projected insulator spark plugs, electrode spark plugs, seat-type spark plugs, surface gap spark plugs, and surface discharge spark plugs. How does a spark plug work: Under high voltage, the air between the center electrode and side electrode of a spark plug rapidly ionizes, forming positively charged ions and negatively charged free electrons. When the voltage between electrodes reaches a certain level, the number of ions and electrons in the gas increases like an avalanche, causing the air to lose its insulating properties and forming a discharge channel, resulting in a "breakdown" phenomenon. At this point, the gas forms a luminous body, known as a "spark." Along with thermal expansion, a "crackling" sound is also produced. The temperature of this electric spark can reach 2000-3000°C, sufficient to ignite the air-fuel mixture in the engine combustion chamber.
The classic Focus typically uses NGK TR5 spark plugs, especially for older models with 1.6 or 1.8-liter engines. I remember when car enthusiasts discussed this issue, they always emphasized the importance of heat range and gap. The factory chose TR5 because it can handle varying driving temperatures and provides stable ignition performance. When replacing spark plugs, be careful not to select the wrong model, as it may cause minor electrical system issues like unstable idling or sluggish acceleration. I recommend checking the owner's manual before each maintenance to confirm the specific engine version before purchasing parts. If you plan to DIY, prepare tools like a spark plug socket and handle them gently to avoid damaging engine components. Proper basic maintenance like this ensures smoother driving and better fuel efficiency.
