Can Vehicles Run on Natural Gas?

The idea of converting vehicles to run on natural gas has been around for a long time. While it is possible to convert a gasoline engine to run on LPG (liquified petroleum gas) or CNG (compressed natural gas), there are several critical considerations and drawbacks to be mindful of.

Conversion to LPG or CNG

There are conversion kits available that allow you to run a gasoline engine on LPG. However, the performance and fuel efficiency may suffer. Additionally, you need to install a high-pressure LPG tank in the trunk, which significantly reduces the available space. You may need to refill this tank frequently, which can be inconvenient. For instance, you could swap tanks at Walmart, Costco, or minimarts. However, you would need to carry multiple tanks on a long highway trip, which is not practical.

Compressed Natural Gas (CNG) Vehicles

CNG vehicles have a specialized tank and a difference in the carburetor fuel delivery unit. These vehicles rely on reciprocating 4-stroke engines that are the same as those used in gasoline-powered vehicles. However, CNG vehicles do not make sense for general use, except for special industrial fleets. The cost and fueling are the main drawbacks. CNG has become more common in some countries and major metropolitan areas in the US, but it still comes with significant engineering challenges and safety risks.

Examples and Drawbacks

Some pickup trucks with nitrogen tanks in the bed have been spotted, but these are not popular due to the inherent risks. For instance, you are driving around with a big, compressed flammable gas tank in your car or truck. Besides the risk of leaks, you must also deal with potential problems like static discharge, intake backfire, and the possibility of a catastrophic explosion. Furthermore, smokers can create an additional risk by lighting up near fueling stations or compressed gas tanks, despite the warnings.

Engineering Challenges and Safety Concerns

Each different fuel type, such as diesel, unleaded gasoline (E0/E10/E15/E85), and propane, requires specific air-to-fuel ratios for proper combustion. This is only the beginning of the engineering challenges associated with different fuels. Additionally, each fuel has specific requirements for fuel system components and pressures. Gasoline engines do not produce the same power when running on LPG or CNG.

Converting a gasoline engine to vapor-fed natural gas or propane with a standard propane cylinder is possible, but it is inherently more dangerous than using a grill. Fuel system leaks and fires are always a possibility. Furthermore, CNG and LPG have a higher potential for a rogue spark from static discharge during fueling, ignition components arcing, or an intake backfire combining with a propane leak to create a disastrous explosion. It is important to note that smokers are a significant risk, with many lighting up near gasoline pumps or propane tanks despite NO SMOKING warnings.

Compressed natural gas and liquified petroleum gas tanks require periodic inspection and certification. They must be mounted in a cage on the vehicle to prevent an explosion from collision damage. However, there is still a risk from road debris causing such a disaster as well.

These safety issues and engineering challenges have played a significant role in the relative absence of LPG and CNG from the marketplace in most areas.