Pollution Engineering Magazine
  Resources
  Archives
  Digital Edition Archives
  Buyers Guide
  Classified Ads
  White Papers
  Industry Links
  Market Research
  Career Center
  Resource Guide
  Current Issue
  Cover Story
  Features
  Columns
  Industry News
  PE Info
  Contact Us
  Media Kit
  About
  Online
  PE Coffeehaus
  PE Partner Blogs
  eNewsletters
  Calendar
  ePE-TV
  Webinars
  Podcast
  PE Learning Center
Search in: EditorialProductsCompanies
How to Calculate MPG
by Roy Bigham
May 20, 2009

ARTICLE TOOLS
EmailEmailPrintPrintReprintsReprintsshareShare

As mandates to improve vehicle gas mileage come down from on high, and new technology gets involved, how can we determine just how to accurately calculate fuel economy?


Right now, a vehicle’s mileage is a very simple calculation. Simply divide the number of miles driven by the number of gallons used over that distance to provide an answer in miles per gallon.

A company plans to bring an H3 Hummer vehicle to show off to congress that the manufacturer claims can get 100 mpg. However, AlternativeEnergy.com experts take exception to that claim and say that the actual mpg should be calculated differently, resulting in only 33 mpg.

This argument seems to me to be just another example of some people wanting to control others. They will go to extremes to make their points. In this case, the manufacturer used the simple calculation that we have used since gasoline was first poured into an internal combustion engine to propel the horseless buggy. AlternativeEnergy.com suggests that an error is introduced because the electrical energy was not accounted for in the equation. They suggest that if you take that into account that the average is 33 mpg and the public is being misled. According to AlternativeEnergy, the 100 mpg figure was derived by starting with a fully charged battery that allowed the vehicle to go 40 miles and then use the gasoline engine to go another 20 miles using 0.6 gallons (60 divided by 0.6 equals 100 mpg).

If people just use a little legwork, the picture changes dramatically. I went to the manufacturer’s website. There is a chart and an explanation on the home page. Certainly, if you start with the parameter that a person drives less than 40 miles each day, there would be no gasoline used. However, the more miles that are driven each day, the more the gasoline engine has to operate and the lower the gas mileage will be. If the H3 is driven over 200 miles each day, the mileage is expected to drop to 33 mpg. The company claims that if you drive 65 miles per day, you can expect to achieve an average of 100 mpg. Long distance drivers achieve double the straight gasoline vehicle because the gasoline engine not only propels the vehicle, it also recharges the batteries.

To me, the question should be what is the goal? In this case, the goal is to use less fuel to travel a specific distance. The company did not try to hide or mislead the public. Calculating mpg should not get unduly complicated. Why some people are determined to tell me what I must drive, how I must dress, how to walk, etc. is just beyond my understanding. To be sure, I drive a Ford Focus, but that is my decision and it should be. I live in the U.S.A. not Myanmar.


Roy Bigham
roy@pollutionengineering.com
Roy D. Bigham has been the editor of Pollution Engineering since 2002. Bigham attended Eastern Michigan University where he majored in chemistry and computer science with an associates degree in mathematics. He has worked as a laboratory technician at a research laboratory, managed an electroplating operation and an associated analytical laboratory. He spent three years overseeing environmental operations of five domestic and five overseas operations for a major manufacturer in the Detroit area. He then managed a field services department for an environmental analytical laboratory before moving on to a position as an environmental engineer for a construction aggregates company.

Bigham won a design award for a waste water treatment system for a landfill in the Detroit area from the State Chamber of Commerce. He has been active in the environmental field since 1980.


|PrintEmail
  Comments (0)Post a Comment
 

No HTML or BBCode in comments please.
 


Did you enjoy this article? Click here to subscribe to the magazine.











BNP Media
© 2010 BNP Media. All rights reserved. | Privacy Policy