The second generation W126 controls ignition timing from the EZL. In most countries, Mercedes-Benz provided a knob to adjust the timing based on the petrol that was available in your area. This knob is present on my UK delivery 560SEC. I immediately turned the knob up to 98 octane petrol, as that is what I use in the car. In markets like Australia and the USA, they did not provide this knob. Instead, they provided a fixed resistor for that market. That allowed them to optimize for the petrol available in that market and focus emissions testing on that. That […]
