Is an ignition advance angle of 12 degrees or 9 degrees better?

[McAriel]

An ignition advance angle of 9 degrees is better, for the following reasons: The ignition advance angle is generally between 6 and 12 degrees. A 12-degree ignition advance angle is too large compared to 9 degrees, which can lead to delayed ignition. If ignition is delayed, the gas will have difficulty performing work, fuel consumption will increase, efficiency will decrease, and exhaust noise will also increase, affecting the engine's working efficiency. Additional information: Ignition advance refers to the spark plug firing before the engine piston reaches the top dead center of compression. The angle through which the crankshaft rotates from the moment the spark plug fires until the piston reaches the top dead center of compression is called the ignition advance angle.

[LilahLynn]

There's no absolute answer whether 12 degrees or 9 degrees of ignition advance angle is better—it really depends on your specific vehicle condition. From my experience repairing many engines, this matter is quite complex. If the car operates at high altitudes or frequently uses low-octane gasoline, 9 degrees is more stable and less prone to knocking. But for those pursuing power, 12 degrees delivers more punch with quicker throttle response, especially suitable for highway driving or hill climbing. However, excessive advance angle increases engine temperature and accelerates piston wear. Modern cars come with knock sensors for automatic ECU adjustment, while for older manual-tune vehicles, it's best to measure cylinder pressure first before deciding.

[LaSteven]

I think whether to choose 12 degrees or 9 degrees for the ignition timing depends on your driving habits. For daily city driving, 9 degrees is more suitable, offering stable fuel consumption and engine protection. But for long-distance driving or racing enthusiasts, the 12-degree setting delivers a real kick-in-the-back feeling. A rally-racing friend of mine mentioned that setting it to 12 degrees gives a powerful acceleration in corners, but it requires 95-octane fuel to support it. Actually, for regular family cars, it's safest not to tamper with the factory settings—keeping it between 8 to 10 degrees is ideal. Getting the ignition angle wrong might even cause your car to fail the emissions test during the annual inspection.

[WilliamLynn]

The selection of ignition timing advance is quite particular. 12 degrees delivers more aggressive power but carries higher risks, especially for older cars - adjusting this parameter improperly may cause cylinder scoring. 9 degrees is relatively conservative and safer, with smoother cold starts. Once when helping a neighbor repair an old Jetta, reducing the factory setting from 14 degrees back to 9 degrees significantly stabilized the idle speed. Modern fuel-injected vehicles don't require manual adjustment - simply reading real-time data through the OBD port can check fault codes. Remember the fuel octane rating determines the upper limit - forcing 12 degrees advance with 92-octane gasoline will definitely cause problems.

[KinsleyFitz]

The key to ignition timing is finding the balance point. 9 degrees is like a moderate approach, with slower combustion and lower temperatures, suitable for stop-and-go city driving. 12 degrees is more aggressive, with faster air-fuel mixture combustion and stronger explosive power, but it's prone to knocking and unusual noises. I've noticed that cars with modified exhausts set to 12 degrees sound particularly loud, but this can shorten the lifespan of the spark plugs. It's advisable to first check the carbon buildup in the throttle body before deciding whether to adjust the ignition angle. The factory settings are the most reliable, but if you must modify, start with 10 degrees and gradually test the vehicle.