Browse Publications Technical Papers 2001-01-3588

No Major Backsliding in Air Quality when Replacing MTBE with Isooctane in CARB Gasoline 2001-01-3588

Plans to ban MTBE (Methyl tertiary-Butyl Ether) have led to discussions on how the gasoline in California will be formulated without any backsliding in air quality. One possibility is to replace MTBE with isooctane.
Exhaust emissions using California Phase II gasoline with MTBE, were compared to a gasoline where MTBE had been replaced with isooctane. Regulated, particulate, carbon dioxide, and PAH (polyaromatic hydrocarbons) emissions were measured at 22 °C temperature for 8 vehicles using the European cycle for year 2000 (ECE+EUDC). One of the vehicles was a GDI (Gasoline Direct Injection), one was a carbureted model without a catalytic converter, and the others were equipped with multi point fuel injection and catalytic converters.
Results indicate that no major backsliding in air quality can be expected when replacing MTBE with isooctane.
NOx (nitrogen oxides) emissions were reduced in all vehicle types. CO emissions increased in the vehicle without a catalytic converter. Differences in fuel consumption and CO2-emissions were within the accuracy of the measurements. Consistent differences were not seen between the fuels concerning PAH emissions or particulate mutagenicity.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:

Effect of Gasoline Reformulation on Exhaust Emissions in Current European Vehicles


View Details


Procedure for the Analysis and Evaluation of Gaseous Emissions from Aircraft Engines


View Details


Exhaust Emissions of an Ethanol D.I. Spark-Assisted Diesel Engine Equipped with a Catalytic Converter


View Details