Compare NG to Fosil

[Ricola]

First question from a new guy with no NG experience.
Pardon if this has been asked a couple hunderd times.
Q. If I get 30MPG with my current fosil car and then convert to NG how many MPG can I expect? Ball park. ie: if it's like 15 mpg what's the point?

[CNGLO]

Re: Compare NG to Fosil

First question from a new guy with no NG experience.
Pardon if this has been asked a couple hunderd times.
Q. If I get 30MPG with my current fosil car and then convert to NG how many MPG can I expect? Ball park. ie: if it's like 15 mpg what's the point?

If you do not convert the engine to take advantage of natural gas' higher octane, you will see about a 10-20% decrease in fuel mileage. Right now, the cost to convert hardly justifies making the change. If you were to buy a used CNG vehicle or a new Civic GX, you still have to drive the car many, many miles to justify the cost. Run the numbers carefully to see how it works for you.

[ajgiorgi]

Re: Compare NG to Fosil

mileage is the same isnt it?

[Beej]

Re: Compare NG to Fosil

I'm driving an '08 Civic GX and getting about 30 MPG on my daily driving around town. I figure I averaged 40 MPG on the freeway driving it up from California (but I was only driving between 65-70 MPH). It can be really tricky to determine exact mileage since you're dealing with pressure, which can be different from fill to fill, instead of liquid gallons which are always the same. As far as I can tell I get the exact same mileage I would have with a gasoline engine in the same car. I don't know if conversions are different, I wouldn't think so.

[CNGfamily]

Re: Compare NG to Fosil

...liquid gallons which are always the same...

Not to be a PITA, but there is a variation in energy content even with liquid gallons of gasoline.
One big factor is temperature... I can tell you that filling up when the ambient temperature is 110F outside in Arizona, you get a fair amount less energy compared to winter temperatures.

In my experience with 3 different bifuel vehicles, I'd vote for a hit to MPG of less than 10%, but a much larger hit to actual power. All three vehicles had plently of engine for the size of vehicle: V-6 Sonoma, 5.4 liter F150 and, and 5.3 liter Tahoe. I don't have evidence, but I'd expect a bigger hit with a smaller engine where you'd be typically be running at a higher % of peak HP.

[Kevin Fern]

Re: Compare NG to Fosil

I just thought I would chime in on this, The milage should be close to the same. The temperature where the gas is stored will play to reduced density overall, but the milage should be the same, just reduced storage in hot areas of the country. The biggest impact of fuel range (gasoline and others) is driver input, its been proven that the mood of a person can effect up to 30% of their fuel usage.

Not to be a PITA, but there is a variation in energy content even with liquid gallons of gasoline.
One big factor is temperature... I can tell you that filling up when the ambient temperature is 110F outside in Arizona, you get a fair amount less energy compared to winter temperatures.

In my experience with 3 different bifuel vehicles, I'd vote for a hit to MPG of less than 10%, but a much larger hit to actual power. All three vehicles had plently of engine for the size of vehicle: V-6 Sonoma, 5.4 liter F150 and, and 5.3 liter Tahoe. I don't have evidence, but I'd expect a bigger hit with a smaller engine where you'd be typically be running at a higher % of peak HP.

[ch4]

Re: Compare NG to Fosil

Not to be a PITA, ...

Is a PITA like a pedant?

[RaulLasVegas]

Re: Compare NG to Fosil

There is more than just an ecomonical reason to use CNG. After reading all that has been said on this site, if the cost were the same (fuel and car) I would still be driving CNG. It is environmentally cleaner, and it supports our LOCAL economy.

As far as fuel density, and summer/winter fills. A GGE is 5.66 pounds of NG. Conservation of mass keeps that a constant amount of energy, dispite the tempurature. Winter fills nets me 7 GGE, summer its 6 GGE.

PITA = Hemorroid