Mail carrier services use a substantial amount of gas as they deliver packages, so it comes as no surprise that they’re also on the forefront of a lot of eco-friendly, fuel-efficient practices. UPS just started substituting diesel fuel with lower-emission liquified natural gas, which is stored at 260 degrees below zero. In fact, a growing number of large trucks are turning to liquefied natural gas as an alternative — especially since diesel prices reached over $5 a gallon in 2008. Natural gas prices, on the other hand, have either dropped or have stayed stable.
UPS is planning to add 48 liquid natural gas (LNG) trucks to its hubs in California and Las Vegas, and it will continue to add more as the fueling infrastructure becomes available. The 15-liter, 450-horsepower engine trucks, will be primarily used on the highways.
According to the NY Times, compressed natural gas is not a practical substitute for diesel for these larger trucks because they burn 20,000 to 30,000 gallons of fuel a year. On the other hand, if these trucks switched to liquefied natural gas we could reduce our oil imports by more than a million barrels a day. The engines ignite the fuel through compression, making them more efficient than spark-ignited engines. Currently the U.S. uses the diesel equivalent of six trillion cubic feet of natural gas.
While scientists are also working on finding renewable alternatives for these trucks, liquefied natural gas seems like the best alternative right now, especially since LNG requires only about 70 percent more space than diesel fuel — while compressed gas needs at least six times that. The trucks use a little bit of diesel to keep the engine lubricated, but usage essentially goes down by about 95 percent.
Currently, UPS. also uses propane, batteries and hydrogen fuel cells to run its trucks. The company received $5.5 million for the liquid gas project from the state of California to help with implementation. Companies like Kenworth, Enviro Express (a Connecticut company that uses trucks to haul trash), and truck maker Peterbilt have all ordered similar trucks.
Clearly, the infrastructure doesn’t exist for all highway trucks to switch to LNG, but if more companies start investing in the engines the set up is bound to follow.
Via NY Times