The higher pricing of natural gas powered heavy trucks along with their limited amount of fueling stations is stunting the increased sales that experts predicted. Nearly 10,500 of the natural-gas-powered heavy duty trucks are expected to sell this year, according to Power Systems Research. That would be a 20% increase from the 8,730 sold last year. Many experts predicted sales would double last years, nearing 16,000 vehicles.

One reason people are shying away from natural gas power is because the price of one is about $50,000 higher than that of a diesel-powered truck. The theory is that the payback for that higher price is recovered in fuel savings being that natural gas is about $1.60-$1.70 per gallon. But it could take about 4-5 years for the money to be reclaimed, considering the average truck travels about 125,000 miles a year.

Also, truckers have argued that this theory doesnt hold true. Mileage from a natural gas powered truck is about 20% less per energy equivalent than your average diesel truck. This means a natural gas truck would consume the same amount of fuel for 100 miles as a diesel truck uses for 120 miles.

Many trucking companies report that they replace their fleets every 3-4 years, which leaves little time to benefit from using natural-gas trucks, if any. Furthermore, the fact that diesel engines are becoming more efficient as time advances makes the lower priced and easy to refuel diesels more attractive.