Hybrids
From Diesel to Hybrid to CNG
Both Compressed Natural Gas and Hybrid technology reduce greenhouse gas emissions, providing a cleaner public transportation alternative and reducing our carbon footprint. It also decreases America’s dependence on foreign oil.
Compressed Natural Gas (CNG):
COLTS has 13 CNG buses and six CNG vans in its Shared Ride division.
Advantages of CNG:
Better gas mileage: CNG buses get nearly 6 mpg, while diesel buses get 4 mpg
Lower and more consistent gas prices
Less maintenance required than diesel
Better for the environment
CNG offers COLTS a more consistent and constant fuel price.
- the price does not fluctuate like the price of fossil fuels does.
- with more stable gas prices, operational costs should be more consistent long-term.
CNG buses are environmentally better than diesel buses. CNG is a cleaner burning fuel and there is no sulfur in it.
Cost of bus comparison:
CNG (2017): $537,168
Diesel (2015): $457,705
Hybrid (2012): $614,394
CNG is the environmentally clean fuel:
- CNG is the cleanest burning fuel today; this means less vehicle maintenance and longer engine life.
- CNG vehicles produce the fewest emissions of any motor fuel.
- CNG produces significantly fewer pollutants than gasoline. This means fewer emissions releasing carbon dioxide and contributing to global warming.
The maintenance advantage:
- Intervals between tune-ups are extended 30,000 to 50,000 miles.
- Intervals between oil changes for CNG vehicle are dramatically extended (anywhere from 10,000 to 25,000 additional miles, depending on how the vehicle is used.)
- Natural gas does not react to metal the same way that gasoline does, so pipes and mufflers last much longer.
The performance advantage:
- CNG buses get better mileage than diesel buses; they are comparable in gas mileage to a hybrid. A CNG bus will get nearly 6 miles per gallon, whereas a diesel get 4 mpg.
- CNG has an octane rating of 130 and has a slight efficiency advantage over gasoline.
- Because CNG is already in a gaseous state, they have a superior starting and drivability, even under sever hot and cold weather conditions.
CNG cost advantage:
- Natural gas is cheaper per equivalent gallon than gasoline (an average of 15% to 50% less than gasoline)
Hybrid Buses:
COLTS has 13 hybrid buses. Hybrid buses are 35 percent more fuel efficient than conventional diesel buses. They run on a combination of electric batteries and clean diesel fuel. Hybrid buses use less fuel because their engines shut down when they come to a stop. As that happens, braking energy is converted into electricity that is stored in the buses’ batteries, which are located on top of the vehicles.
Hybrid buses reduce noise pollution, providing a smoother, quieter ride, enhancing the experience for COLTS passengers and the surrounding community.

