Info on CNG / DIESEL bi-fuel

[Brimmy]

I am wondering what the forum opinions are on bi-fuel. Looking at a 6.6 with a CNG kit on it. Runs fuel blend of 70/CNG - 30/DIESEL. Lets hear what you think or have experienced .. :)

[Mark Rinker]

Welcome aboard - and thanks for your interesting post. First, a few questions:

1) Is this an OEM, GM offering?
2) Can you post a link to more information on this truck?

I experimented with a digital system injecting LP gas over diesel on a 2001 Duramax. My findings?

It all comes down to the cost/BTU that you can source the secondary fuel, relative to the cost/BTU of the primary fuel.

Grasp that, build a spreadsheet to monitor the combined vs single fuel MPGs and examine the results of burning two dissimilar, variable priced fuels, and you'll have the answer.

My guess? Straight #2 diesel will make more power, but cost more per mile. However, if you can source CNG for less cost per BTU, have access to a CNG fueling station, ...well...you might be on to something! I do know that when you add a vaporous fuel into the intake of a turbo-charged diesel, you can make GOBS of power, and in the right proportions, create a very clean burning diesel.

It will be interesting to find out more about this truck and system. If they REALLY have this figured out, the truck will need to know the cost of each fuel you are burning to come up with the optimal mixture, under different load conditions, to make this all work out. Simple stuff, but complicated to get such a product to market, compared to a single fuel, single purpose vehicle!

Keep us up to date!

[More Power]

According to the Energy Information Administration: (http://www.eia.doe.gov)

1 gallon of gasoline = 124,000 Btu
1 gallon of diesel fuel = 139,000 Btu
1 gallon of heating oil = 139,000 Btu
1 cubic foot of natural gas = 1,031 Btu
1 gallon of propane = 91,000 Btu

1 barrel(42 gallons) of crude oil = 5,800,000 Btu
1 short ton of coal = 20,754,000 Btu
1 kilowatthour of electricity = 3,412 Btu

[Brimmy]

Mark, Check pm. I sent you what info I found.

[Mark Rinker]

I answered your PM, can you post the content here for all to share?

First step: Find out what the BTU/gallon of compressed (CNG) natural gas is, the availability and cost per gallon...(don't forget to factor in the cost of the pumping station, and the recent price hikes in residential NG, if you plan to do this yourself...also ask your gas company..."How much is a 'therm'?"... Hmmmm....)

I'll walk you through why this is NOT a money saver...no free lunch. ;)

[Brimmy]

Ok, This is what info I have found on the truck.
2003 GMC 2500HD Crew Cab. 96000 miles.
The CNG conversion kit is a "DeLuca CNG kit"
Marc Deluca

www.delucafuelproducts.com

www.delucafuelproducts.com/Compressed Natural Gas.htm


They list as :

CNG/Diesel Bi-fuel 4WD GMC Duramax SLT. This is one sweet truck. Not your typical CNG fleet truck. It comes with 4 doors. It has amazing power & torque.
200 +- mile range per tank on CNG. 70%CNG/30%Diesel.
Your average fuel cost per gallon is about $1.90 depending on driving conditions, speed, load, etc.


Anyone else with CNG data for 6.6 Duramax ??

[Mark Rinker]

Your average fuel cost per gallon is about $1.90 depending on driving conditions, speed, load, etc.


Ask yourself how this claim can this be possible, when the first gallon of two fuels you will be driving costs ~$4/gallon? Unless someone paying you $3.10 to burn each gallon of CNG, you aren't burning two fuels together and ending up with $1.90 per gallon fuel cost.

If someone is paying me to burn CNG, where do I sign up for that program??? Is that the same place Bill Gates is giving away his millions??? :D

Do the math. You will be burning two fuels simultaneously, so add the cost of both fuels together...drive the miles, then divide by total gallons burned, and total cost of both fuels.

The only meaningful cost comparison is cents/mile on #2 alone, vs. cents/mile on the combined cost of both fuels burned.

Range is one thing. More power is another. Asking for more range and more power for less money isn't realistic. 1+1=2, not 2.1 or 2.2 or ... no free lunch.

Also, are you impressed by the HUGE tanks used for the CNG? The pickup bed is consumed by the tanks!!!

[More Power]

T Boone Pickins and others have suggested that homeowners could install a refilling station in their garage, which compresses the NG, and will allow owners to refill their own vehicle's CNG tank.

In my opinion..... It'll never be allowed to happen because it takes the gov out of the revenue stream. I also feel the same way about electric cars - great idea, but the gov won't likely get behind it for the same reason. Unless perhaps, the gov sets up registration stations that require all electrics to get their tamperproof odometers read every year, and then pay a road tax equivalent to what a gas burner would pay for the same number of miles. :(

Jim

[Mark Rinker]

T. Boone Pickens must have an equity stake in one of the CNG hardware companies, the NG companies, or both.

I suspect if I had the correct data to convert from 'therms' (the only measurement on my natural gas bill) to calculate the BTU equivalent, CNG would be much more expensive than #2 diesel...