It also allows the compression ratio of the engine to be raised well above normal, which results in more power and better fuel economy. Unfortunately, this change also increases the NOx gases in the exhaust, which requires wnat's known as a de-NOx catalytic converter. While this works, de-NOx catalytic converters cannot work with gasoline that have more than 10 parts per million of sulfur compounds. With the new EPA requirement that all gasoline must be limited to no more than 10 ppm of sulfur compounds, that makes de-NOx catalytic converters viable, making it possible for more powerful GDI engines with lower fuel consumption.
So would this mean new federal requirements for auto manufacturers going forward? Is this something that’s going to increase the cost of our next cars?