Hey gang, CNGchat needs your help!

For over a decade we have enjoyed providing this little corner of the Internet for folks to discuss all things natural gas vehicles. It is the largest forum of its kind: with some 70,000 posts on over 11,000 topics. But with continued low gasoline & diesel prices and strong automaker support for electric vehicles, consumer interest in CNG has dropped considerably, and with it has visitor traffic here. As a result, Google ad revenues no longer cover hosting fees.

If you find CNGchat to be a useful resource then please consider making a modest donation to support keeping this remarkable pool of knowledge available to the alternative fuels community. Thanks!

See more
See less

Gas mileage

  • Filter
  • Time
  • Show
Clear All
new posts

  • Gas mileage

    Hi, everyone. I have a 2014 Honda CNG. I just checked the mileage and I'm only getting 150 miles to the tank. I also can only fill five gallons. It's very strange. Everyone I encounter says they can only fill five gallons at a time. Why does it only take five gallons?
    Also what kind of spark plugs does everyone use??

  • #2
    That is normal. " Range" . I bet your " Mileage" is around 30. In close to 200k miles on my '01 GX and '08 gx , most station fills were about 5.5 gallons equivalent. The most I ever got was 7.2, and that was a tow in to the station after running out. If you search the Honda Civic Sub Forum, you can find dozens of threads on exactly why.

    Use the oem plugs. Nothing magic about them , except they are nickel plated to combat the very corrosive conditions encountered in CNG. Cng can have a lot of water in it and still be considered sufficiently dry. This causes a corrosive environment in the combustion chamber.The owners manual will have both an NGK and Denso plug numbers. . They are very expensive at the dealer ($25 +ea ) Can be found for about half that online. Bernardi Honda Parts

    PS it is a very good idea to remove and reinstall the plugs every 2 yrs / 25k miles so they don't seize up in the head.Use a torque wrench. Inspect the coilpacks for fine cracks and arc marks at the same time The OEM plugs should last over 100k Miles. Have intake valves adjusted every 30-50 k miles.