(This article contains excerpts from an article by Sean Nealon, published in UCR Today, on May, 7, 2014.)
UC Riverside graduate student works with Motor Trend magazine to create fuel economy ratings for vehicles based on real-world driving, not lab tests.
Sam Cao, a UC Riverside graduate student, who tested cars in conjunction with Motor Trend. Photo Credit: UCR Today
Do you ever wonder about the accuracy of those miles per gallon ratings pasted on windows of new cars?
So did Emissions Analytics, a United Kingdom-based vehicle emissions testing company. With the help of Sam Cao, a graduate student at the University of California, Riverside’s Bourns College of Engineering, they set out to test the accuracy, but with one significant difference.
Those numbers are based on a standardized test procedure performed in a laboratory by the Environmental Protection Agency (EPA). Emissions Analytics placed portable emissions measurement equipment on vehicles to test fuel economy while the cars were being driven on the road.
They found differences – up to 20 percent. Some cars fared better than EPA estimates, some worse and some about the same. For example:
- A 2013 Honda Accord LX four-door sedan had an EPA rating of 27 miles per gallon on city streets and 36 miles per gallon on highways. The Real MPG, as Emissions Analytics calls their figure, was 19.8 city and 33.6 highway.
- A 2014 Volkswagen Jetta 1.8T SE four-door sedan had EPA ratings of 25 city and 36 highway. The Real MPG numbers were 27.9 city and 39.2 highway.
- A 2014 Chevrolet Camaro ZL1 two-door convertible had EPA ratings of 12 city and 18 highway. The Real MPG numbers were 12 city and 18.9 highway.
Cao, who works under Kent Johnson, an assistant research engineer at the Bourns College of Engineering Center for Environmental Research and Technology, worked with Emissions Analytics during the summer of 2013 as they tested vehicles at Motor Trend’s office in El Segundo. Cao, a 2006 graduate of Temecula Valley High School who expects to earn his Ph.D. in June, has worked extensively with portable emissions measurement equipment at UC Riverside.\
A vehicle with portable emissions testing equipment is readied for on the road testing. Photo Credit: UCR Today
While working with Emissions Analytics, Cao’s duties included installing the measurement equipment, trouble-shooting data acquisition problems and calibrating the instruments. Cao’s work on the project is one of the latest examples of a more than 20-year history of emissions testing at the Center for Environmental Research and Technology. Initially, research focused on testing cars and trucks in a stationary setting. Now much of the testing is done on the road with portable emission measurement systems (PEMS).
Cao and Riversides’s Bourns College of Engineering exemplify seizing our destiny’s intelligent growth and catalyst for innovation pillars. Comparing accurate MPG estimates are important, and has become a crucial factor to many people when choosing a new vehicle. The people and educational institutions of Riverside cultivate and support beneficial ideas and research. Creativity and innovation permeate all that we do, which makes our community a trendsetter for the region, California, and the world to follow. Riverside promotes an outstanding quality of life for all through intelligent growth.
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