As you may know, EPA is moving to further reduce gasoline sulfur by 2017 in US gasoline blends. The main purpose is allow improved catalytic converter performance, whereas sulfur inhibits the catalyst efficiency. Improved catalytic converter performance should equate to improved air quality at least in some areas. California apparently already has the lower sulfur. I am posting this partilcular article because it talks a little about impact on car design: I wonder if in the future all hybrids will be CARB certified. Also some here say non-CA Prius are already exactly same as CA Prii, but I wonder if catalyst element is the same. US EPA orders sharp cut in gasoline sulfur content starting in 2017 - Oil | Platts News Article & Story
I state it is the same the emission controls are the same because the EPA engine codes are same. These can be found under the environment entry of the car on Fueleconomy.gov, or on a sticker under the hood. It used to be common that cars had different codes for CARB and federal states. When building a car online, at least when the location chosen was a border area, you were given the option of getting the CARB emission package. The only model of the top of my head that still has the choice, and different engine codes, is the Volt. The gap between CARB and federal limits has closed. Plus the car companies may have been proactive with this ULS gas being originally planned for 2012.While the 30ppm sulfur of federal gas may decrease catalytic convertor effectiveness, it doesn't seem to be a concern for limiting its life. I haven't heard of any warnings that a car with a California emission system should avoid or limit the amount of higher sulfur federal gas it should use at least.
The higher quality the fuel, the less expensive it is for automakers to design equipment. Lower sulfur fuel would allow for less expensive cats hitting the same standards, or a smaller increase in cost to meet more stringent standards. Lowering the minimum sulfur is good for car makers, but if you raise standards arbitrarily on pollution it may not be good for consumers. Oil refiners also benefit from higher standards as they can then pass along higher fuel costs to consumers. The oil companies problem is they picked 2017 instead of 2019 for the standards, and this may have them rush the process, making mistakes that increases costs more. Simply raising fuel taxes might be better public policy, idk, it depends on how much this adds to fuel costs versus car equipment. Lower sulfur would allow for a less expensive catalytic converter, but California drivers, drive out of state, where they their cheaper cats might be poisoned by filling up in nevada or other states. I would bet every automaker is building cats for the federal gasoline standards. All of the hybrids meet CARB standards today other than waranty requirements, but at least the volt, has a special California version, that complies with the pzev catagory in california so that it can get HOV stickers.
It's been 10 ppm here for years. Deadline was 2009 but UK suppliers met the requirement in 2007. All helps I guess.
