Study claims hybrid cars not energy efficient
20 April 2006
Driving a hybrid vehicle costs more in terms of overall energy consumed than comparable non-hybrid vehicles, according to a study by auto market firm CNW Marketing Research. The study—titled “Dust to Dust” Automotive Energy Report—is a “well-to-wheel” type of analysis that takes into account not only the energy needed to drive a vehicle, but also the energy necessary to plan, build, sell and dispose of the vehicle from initial concept to scrappage.
CNW spent two years collecting data for the analysis, which includes such details as plant to dealer fuel costs, employee driving distances, electricity usage per pound of material used in each vehicle and hundreds of other variables. To put the data into understandable terms for consumers, the results have been expressed as the energy cost per mile driven (“dollars per lifetime mile”).
The study concluded that hybrid vehicles had higher energy costs than the corresponding non-hybrid vehicles. For example, the Honda Accord Hybrid has an energy cost per mile of $3.29, while the conventional Honda Accord is $2.18. In other words, the Accord Hybrid would require about 50% more energy over its lifetime than the non-hybrid version.
One of the reasons hybrids cost more than non-hybrids is the manufacture, replacement and disposal of such items as batteries, electric motors (in addition to the conventional engine), lighter weight materials and complexity of the power package.
Another surprising finding of the report is a relatively low energy cost of larger size vehicles. For example, while the industry average of all vehicles sold in the USA in 2005 was $2.28 per mile, the Hummer H3 (among most SUVs) was only $1.949 per mile. That figure is also lower than all currently offered hybrids and Honda Civic at $2.42 per mile.
The report also rated GM Tahoe, a large SUV model, as having the same lifetime energy cost as Honda Insight, a hybrid with the highest EPA fuel economy rating ($2.937 and $2.939 per mile, respectively). The low lifetime energy cost of heavier vehicles is explained in part by their longer life expectancy.
“Well-to-wheel” analyses are very complex, as the results depend on hundreds of assumptions, many of which are arbitrary and prone to bias. The CNW report contradicts a number of earlier studies (including studies by the Massachusetts Institute of Technology in 2000 and 2003; a joint study by General Motors and Argonne National Laboratory of 2001; analysis by the Australian Greenhouse Office of 2001; and study for the Swedish National Road Administration of 2001) which assigned high energy efficiency ratings for hybrid vehicles.
The study was self-funded by CNW. The final report is expected to be available as a paid download from the CNW web site in the beginning of May.
Source: CNW Marketing Research