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merle&louise
04-27-2011, 08:49 AM
Bonne Pickens was on Fox Business news this morning discussing the conversion of heavy duty trucks to Compressed Natural Gas. He said we have plenty of NG, it comes out of the ground at around 130 octane, and it would reduce our dependence on foreign oil.

I remember reading that it costs about $65,000 to convert a diesel engine to use CNG. I would assume that as time goes on that price will come down due to competition.

If America's truck stops install CNG pumps and if the price of CNG is much lower than diesel - WOULD YOU CONVERT YOUR COACH TO CNG?

Pete
04-27-2011, 09:33 AM
Tuga, after you do the math let me know if it makes sense.....I will have E.J. put it in the budget!

ajducote
04-27-2011, 10:04 AM
I did a little research on google this morning.
Sounds like there are 2 ways to covert.

1. Go totally to CNG, replace diesel completely. Very expensive.

2. Do a dual fuel system, still use diesel, but add CNG as a second fuel. This seems to be a lot less expensive.

BUT, it looks like a lot of talk and no specifics and I could not find anything on the cost or size of the tanks needed for the CNG.

My concern would be the tank, how big is it, where will it go, how much does it cost?

payback could take a LOT of miles.

maybe some of our bus / truck fleet owners have more detailed information.

There is also a process to turn NG into diesel, but not sure what a gallon of that would cost.

With prices going up, I bet a LOT of snake oil salesmen will offer magic solutions to our problem of high diesel cost.

merle&louise
04-27-2011, 11:06 AM
Tuga, after you do the math let me know if it makes sense.....I will have E.J. put it in the budget!

Hey Pete, you're right it would take us 250,000 miles to recoup our investment. Too long!


One benefit I am starting to see is that if the national fleet of trucks switch to CNG the price of diesel should fall because of less demand. While the conversion doesn't seem to be of much benefit to RVers, the truck fleets who drive 200,000 miles per year could recoup their costs in short order.

Jon Wehrenberg
04-27-2011, 11:21 AM
While cheaper fuels appear attractive to us keep in mind no economic study is complete without considering the BTU content of the cheaper fuel.

I don't know the specific BTU content of the various fuels, but I do know diesel fuel has one of the highest, if not the highest meaning it can deliver more power per gallon than most if not all others. We already see the impact when we buy fuel for our cars. The BTU content of pure gasoline is much higher than an ethanol blend and the distance travelled on the pure fuel is greater than the blend.

I carry 298 gallons of diesel. I cannot imagine trading that capacity for a smaller tank of alternate fuels such as CNG, which has to be a pressure vessel. And then not only have less fuel, but to travel less distance per gallon. I am sure fleet owners feel the same way.

Want to reduce fuel consumption? Drive slower, reduce the weight of the coach, avoid hilly terrain, don't pull a toad, no idling, etc.

GDeen
04-27-2011, 12:21 PM
This is the future guys. Everyone wants to reduce our dependence on foreign oil, and the transportation sector ultimately has to come up with alternative fuels. And windmills and solar obviously aren't the answer.

Natural gas is the answer. The current paradox is that demand is not high enough to generate interest in widespread fueling stations. Without widespread fueling options, fleets and consumers aren't going to convert. Pickens is leading the charge in getting fleet incentives enacted to kick off the process. If the government is going to spend our tax dollars subsidizing alternative fuels, this is one place they should focus as it is the best opportunity to relieve the pressure on imported liquids (oil).

We have discovered enormous reserves of natural gas on American soil over the past 10 years or so. Moving in this direction means American jobs, and large amounts of cash infusion into local American economies. It is a great answer to the problem of increasingly limited supplies of liquid hydrocarbon fuels.

As to our own needs and economies, A1 is exactly correct. It will be a while before this is viable at our level. But, without it, I guarantee we are faced with much higher trending fuel prices for our hobby.

merle&louise
04-27-2011, 01:24 PM
I found this by doing a search on Google.

http://www.socalgas.com/ngv/residential/fuelcomparison.html

Jon Wehrenberg
04-27-2011, 02:12 PM
Tuga, Since SoCal gas put that out it is no wonder they did the comparison on the pure cost per gallon and did not reflect the cost per mile per gallon which would bias the comparison towards diesel.

I have no skin in the game when it comes to which fuel to use. But unless science changes things it is likely the vehicle and its use will dictate which type of fuel to use. We may have an abundance of natural gas, but the problems associated with using that for heavy commercial vehicles is likely to make its use impractical. I may however be ideal for cars, city buses, police cars, industrial vehicles like fork trucks, or utility machines like lawn mowers.

travelite
04-27-2011, 06:17 PM
Turns out CNG is sold in GGE's, or Gasoline Gallon Equivalents. One GGE of CNG contains 5.667 kg of methane. This has the same energy content as a gallon of gasoline, or 115000 BTU's. The ratio of gasoline to diesel energy content is 0.88. So if you can go 7 miles on a gallon of diesel that equates to 6.16 miles for a gallon of gasoline which equates to 6.16 miles for a gallon of CNG. This is true cause by definition: a gallon of CNG has the same energy content as a gallon of gasoline. At the CNG pump you need to buy 13.6% more to get the equivalent diesel energy content which means when comparing the price to a gallon of diesel multiply the CNG price per gallon by 1.136.

This assumes the engine is as efficient burning CNG as it is burning diesel.

http://en.wikipedia.org/wiki/Gasoline_gallon_equivalent

Compressing and storing CNG at 3500 psi means Jon's 300 gal tank can hold 80 GGE's of CNG giving the bus a range of 486 miles.

Current CNG prices are around $1.85 per GGE or $2.10 for a diesel gallon equivalent.

Would you be willing to stop for fuel every day if you could save 1/2 your annual fuel budget?

Someone may want to check my math. :)