[Nerys]

so to go 36 miles in the CNG car it would cost $1.92 IF you had gas pumped to your house (CNG at the gas station WILL cost more I think I can say with 99% certainty) and IF you had the special equipment needed to use your house gas to fill your car.

while the gasoline car also getting 36mpg would cost me $2.34

so the CNG car would only save me 42cents a gallon but REQUIRE me to buy a NEW car at a $7000 premium AND have home pumped CNG gas AND have the very expensive home equipment to fill the car.

for 42cents a gallon savings? no thanks.

Like I said it would never save me a single penny in gas savings since the ROI on the extra cost (and prices continue to rise mind you yet gasoline prices are currently falling though I will admit we all know that won't last) back on track the ROI at a rough guess is many times longer than the expected lifespan of the car.

Thank you chuckm for providing the numbers on how much gas it consumes!

now if you DO have home pumped gas and already have needed home equipment (or a local filling station) and assuming you can get that price for residential fuel it MIGHT be worth it.

its NEVER worth it over keeping your current car (finance charges cost of car cost of full coverage insurance make the gas savings seem tiny) but lets assume YOU WILL be buying a brand new car either way and you will be buying a civic so your out of pocket is $7000 extra. (I have no idea what the home equipment costs I imagine a lot so lets assume you have a local filling station and they charge residential pricing (a lot to assume but lets go with it))

$7000 turns into $10,500 after finance charges and thats being very generous ie decent credit low interest rate 5 year loan. Interest WILL be in excess of 50% but again lets assume you get lucky so use 50% interest.

I drive 40,000 miles a year. almost 4 times the national average.

at 36mpg I would use or 1100 units of fuel.

CNG $2112
Gas $2574

We will assume the prices will stay static NOTE gas is going down while CNG is going up AND this assumes you can get a local filling station to charge you residential pricing and ignores the gas tax that would be added to this and the higher profit of a gas station.

Savings $462 per year under BEST possible condition.

ROI is just shy of 23 YEARS and thats at 40,000 miles per year.

ahh No. that just won't work :-) this means the AVERAGE person would require 82.5 YEARS just to break even before they would save ONE PENNY over just buying the gasoline civic.

and again this assumes CNG prices remain static and you can get residential priced CNG from a local filling station.

as soon as you have to pay more and add home filling equipment your into more than a CENTURY to break even.

heck lets assume you are filthy rich and you pay CASH for the car. NO finance charges at all. so just $7000 premium. (at which point you also won't be caring about the price of gas but again lets roll with it)

15 YEARS to break even. AT 40,000 miles a year.
54 YEARS for the average american before break even.

so NO CNG just won't cut it. Average person keeps there cars today for 9 years (the longest in a long time)

In order to save a penny in gasoline you would have to save $777 per year in fuel savings. the only way to do that is if gasoline costs

hmm average person would currently spend CNG cost for average person (11,000 miles per year) is $586 that means GAS would have to be $1363 per year or $4.47 a gallon.

thats to BREAK EVEN on fuel costs in NINE YEARS. ie you save NOTHING you just break even.

I would say to make CNG desirable to people either the cost of CNG would have to be cut IN HALF and that would be BARELY enough to get people a little interested OR gas would have to be $8 a gallon WITHOUT CNG going up in price.

BTW this is a good segway into why I want a battery electric (but can not afford one right now since I would have to pay 100% up front and not finance it)

there is a Electric metro on craigslist right now that JUST MIGHT work for me. claims 45-80 miles range but I am not sure if I can get my needed 60miles with 4 people in the car but lets pretend I could

$12,000

I spend as we did already $2547 in gasoline (actually I was spending some $4000 a year in gas the METRO I have is going to change that dramatically)

The batteries would need to be replaced every 3 years since they are lead acid batteries. They are sometimes good to 4-5 years but I would be below my minimum required range before then so lets use 3 years.

$2000 to replace the pack. I would have to do that once before ROI about 1 year into the second battery pack before ROI so lets call that another $700 for battery

$12,700 + electricity to charge the car lets assume using straight grid power NO solar offset etc.. which I would do but lets go with it. $300 a year.

5 years to pay for the car. another what? 8 months to pay for the electricity used in that 5 years $1500 so the ROI is a little less than 6 years.

compare that to my NON metro car and the ROI is 3.5 years.

hence why I want a battery electric car so badly but we can't have the affordable NIMH packs we need so that won't work :-(