CNG fuel vs Gas?

Question

Some vehicles, primarily utility pickups, can use gas or CNG.

Are there fuel efficiency advantages? Is CNG cheaper per mile?

How available is it around Southern California?

Answer 1

CNG burns cleaner.  It has less potential energy than gas so it takes a little more to go the same distance.  It's cheaper per mile.  There is limited availabilty of places to refuel.  Some municipalities and counties sponsor stations as well though.

The U.S. Environmental Protection Agency calculated the potential benefits of CNG versus gasoline based on the inherently cleaner-burning characteristics of natural gas, summarized in Clean Alternative Fuels: Compressed Natural Gas

Reduce carbon monoxide emissions 90%-97%

Reduce carbon dioxide emissions 25%

Reduce nitrogen oxide emissions 35%-60%

Potentially reduce non-methane hydrocarbon emissions 50%-75%

Emit fewer toxic and carcinogenic pollutants

Emit little or no particulate matter

Eliminate evaporative emissions

Answer 2

You could buy a Honda car, but somebody is making it very difficult to use alternate fuels, while Industry has been using alternates forever.