However, there may be a solution. EMTA Holdings Inc., an energy conservation company, has created XenTx Extreme Engine Treatment. XenTx reduces overall friction and mechanical wear, resulting in greater fuel economy. XenTX also reduces emissions.

Mesilla Valley Transportation of Las Cruces, N.M., and El Paso, Texas, has been using the treatment and increased its fuel economy 5.1 percent in the first quarter, which will increase the company's savings by about $160,000 per month.

So far, the company has used XenTx engine treatment in 480 of its trucks, said Ernie Simmons, maintenance director for Mesilla Valley Transportation.

Burning fuel produces emissions of carbon dioxide, the most prevalent greenhouse gas. Greenhouse gases create a "blanket" that prevents ultraviolet rays from leaving Earth's atmosphere, resulting in a "greenhouse" or warming effect, according to the EPA.

The greenhouse effect is a major contributor to global climate change. Consuming 35 billion gallons of diesel fuel produces more than 350 million metric tons of carbon dioxide each year.

Burning the fuel also produces nitrogen oxide emissions, which contribute to ozone formation, or "smog," and particulate matter - two air pollutants that have serious health and environmental impacts.

XenTx products are available at most major retailers nationwide, including Wal-Mart, Kmart, AutoZone and Pep Boys. For more information, visit www.xentx.com.