| Volume 12 | No. 3 | Summer 2010 |
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Dialogue |
The environmental performance of hybrids varies from model to model depending on which fuel-saving and emissions-reducing technologies automakers have chosen to embrace. Hybrids provide the greatest benefit to the consumer when they combine three distinct features: idle-off, which turns the gasoline engine off when stopped; regenerative braking, which charges the battery using some of the kinetic energy typically lost through the brakes; and power assist and engine downsizing, which combines a smaller, more efficient gasoline engine with an electric motor that helps propel the vehicle. "Full" hybrids go a step further with electric-only drive at low speeds.
Some automakers do not use these technologies to their full potential, shortchanging consumers on fuel economy and emissions. However, technology is not the sole factor to consider when assessing hybrid performance; the UCS Hybrid Scorecard (online at HybridCenter.org) can help you find the best hybrid for your unique needs and budget by rating each model on fuel economy, emissions, and overall "hybrid value" (a measure that suggests whether a given model gives you a good environmental bang for your buck). We also consider the impact of what we call "forced features": pricey extras included as standard equipment on a hybrid model but not its base-model conventional counterpart. These extras—totaling as much as $17,000—can make an otherwise affordable vehicle prohibitively expensive for many consumers.
Also in this issue of Earthwise:
Close to Home
The Climate-Friendly Gardener
