This is because internal combustion engines, such as those used in natural gas vehicles and in today's gas - powered automobile fleet, are incredibly inefficient. (earth-policy.org)
Since heavy - duty vehicles are expected to account for 40 percent of increased oil use through 2030, we will encourage the adoption of heavy duty natural gas vehicles as well. (climatesciencewatch.org)
Its low speed and short range rule it out as a viable gas vehicle replacement on highways and larger roads, but it does have one advantage - price. (treehugger.com)