What is the normal range for ignition advance angle?
3 Answers
Ignition advance angle normally ranges from 6° to 12°. Here is relevant information: Ignition advance angle: The crankshaft rotation angle from the ignition moment until the piston reaches the top dead center of compression. The ignition advance angle that enables the engine to achieve optimal power, fuel economy, and emissions is called the optimal ignition advance angle. Additional information is as follows: 1. The minimum ignition advance angle is 0 degrees, but to prevent power loss, it is usually set above 6 degrees, which is also the required rotation angle for starting the car. Of course, the maximum ignition advance angle should not be too large, generally not exceeding 60 degrees, otherwise it may cause vibration, leading to engine overheating and a significant drop in engine efficiency. 2. An appropriate ignition advance angle can maximize the mechanical work done by the engine in each cycle. If the ignition advance angle is too large, it may cause knocking. If the ignition advance angle is too small, the engine temperature will rise. The biggest factors affecting the ignition advance amount are speed and the combustion speed of the air-fuel mixture. 3. The ignition advance angle is not fixed and changes with the engine's operating state. Temperature also varies continuously. Generally, the ignition advance angle for gasoline engines is around 10 degrees, while for diesel engines, it is around 15 degrees.
Back when I drove the old Santana, I specifically studied the ignition timing advance. It's definitely not a fixed value—it varies significantly with engine speed and throttle depth. At idle, it's around 10 degrees, while at high speeds with deep throttle input, it can jump to about 35 degrees. I remember one time when the car lacked acceleration power, and it turned out the advance angle was set too high, causing knocking. Nowadays, new cars adjust it automatically via the computer, but for older manual-adjustment vehicles, 6-12 degrees is considered a safe range. The octane rating of the fuel also plays a role; with 98-octane fuel, you can typically set the advance 3-5 degrees higher than with 92-octane. When adjusting, you need to check the distributor marks, and it's best to use a timing light for calibration.
Last week I helped my friend adjust the ignition timing on his modified Civic, and realized there's quite a science to it. For normal driving, it mostly fluctuates between 20-35 degrees. When RPM exceeds 4000, you need to adjust towards 40 degrees for sufficient power. But never exceed 45 degrees - the pistons can't handle it. Different gasoline engine designs vary significantly, with turbocharged cars being more conservative than naturally aspirated ones. During adjustment, I first read the trouble codes, monitored real-time data via OBD interface, and gradually tested to find the optimal angle. The advance angle should be smaller during cold starts, then increased after the coolant temperature rises for stability.
