www.tdiclub.com

Economy - Longevity - Performance
The #1 Source of TDI Information on the Web!
Forums Articles Links Meets
Orders TDI Club Cards TDIFest 2016 Gone, but not forgotten VAG-Com List Unit Conversions TDIClub Chat Thank You




Go Back   TDIClub Forums > VW TDI Discussion Areas > Alternative Diesel Fuels (Biodiesel, WVO, SVO, BTL, GTL etc)

Alternative Diesel Fuels (Biodiesel, WVO, SVO, BTL, GTL etc) Discussions about alternative fuels for use in our TDI's. This includes biodiesel WVO (Waste Vegetable Oil), SVO (Straight Vegetable Oil), BTL (Biomass to Liquid), GTL (Gas to Liquids) etc. Please note the Fuel Disclaimer.

Closed Thread
 
Thread Tools
Old May 22nd, 2012, 11:45   #1
CNGVW
 
Join Date: Sep 2009
Location: Bob Mann Auto, 111 High St, Pembroke MA 02359
Fuel Economy: Built a 2002 TDI Jetta that got 120 mpg of diesel using a CNG blend.
Default VW TDI Diesel Gets 120 MPG on one Gal of Diesel with CNG blend!!

VW TDI Diesel Gets 120 MPG on one Gal of Diesel with CNG blend!!
I will give the math up front. 2001 VW TDI 129 K using my new CNG blend test system.
Round trip 90 % Highway 75-80 MPH.
60 Miles round trip used .51 Gal of Diesel and 1.2 GAL (GGE) of CNG yes I have the slips.
That is a 60% blend of CNG it has very smooth power to boot.
The EGT never went over 990F on long uphill pulls.
Using this system should give you a 70% reduce in fuel cost per mile traveled
If I do the math right here on an average a TDI gets 45 MPG at $4 a GAL that is 11.2 cents costs per mile traveled.
Using a CNG blend system it cost 03.3 cents per mile traveled on Diesel. CNG cost per mile traveled is
.02 cents at $1.00 a GAL (GGE). If I did the math right someone please check it that is a cost of
05.2 cents per Mile traveled a savings of 58.2 %. I pay for home fueling now .40 cents a GAL that should push me in the 80% saving on fuel cost.
I have over 1000 miles on this test system no codes just works.
Bob Mann
CNGVW is offline  
Old May 22nd, 2012, 12:03   #2
tonystdi
Veteran Member
 
tonystdi's Avatar
 
Join Date: Jul 2009
Location: Chesapeake, Va
Fuel Economy: 50+ mpg, 800 mile club
Default

What it cost for the conversion and who is doing it?
__________________
TonysTDI 2003 VW Jetta TDI, 705k+ miles,
miles, 2000 VW Jetta TDI 314,000 miles, 800 mile club, 1990 VW Vanagon
705,000 miles......looking for one million! AARODRIGUEZ CORP.
tonystdi is offline  
Old May 22nd, 2012, 12:04   #3
Rickstah
Veteran Member
 
Rickstah's Avatar
 
Join Date: Feb 2002
Location: Yukon, Oklahoma
Fuel Economy: 49/45/41
Default

Impressive tech, Bob! I'm sure your efforts are covered somewhere, but is there a place where we can follow this, because I have questions about bulkiness, costs for equipment, how to fit into a Jetta, for example, thanks!
__________________
Unnamed green 2002 NB, Malone Stg 1, 2" suspension lift
Rickstah is offline  
Old May 22nd, 2012, 12:21   #4
WutGas?
Veteran Member
 
WutGas?'s Avatar
 
Join Date: Feb 2012
Location: Oklahoma City
Default

And here we go.....
__________________
WutGas? is offline  
Old May 22nd, 2012, 12:33   #5
FSBruce
Member
 
Join Date: Feb 2011
Location: Augusta, ME
Fuel Economy: Just joined the 800 club!
Default

This would make the 110 mile commute a lot more bearable
FSBruce is offline  
Old May 22nd, 2012, 12:37   #6
Rickstah
Veteran Member
 
Rickstah's Avatar
 
Join Date: Feb 2002
Location: Yukon, Oklahoma
Fuel Economy: 49/45/41
Default

Lol, TJK, was this done already while I was gone from this place?
__________________
Unnamed green 2002 NB, Malone Stg 1, 2" suspension lift
Rickstah is offline  
Old May 22nd, 2012, 13:46   #7
CNGVW
 
Join Date: Sep 2009
Location: Bob Mann Auto, 111 High St, Pembroke MA 02359
Fuel Economy: Built a 2002 TDI Jetta that got 120 mpg of diesel using a CNG blend.
Default

Hello it has been talked of here. But I have built the system round a simpler way I think.
I would like for someone to post the fax number for Fred’s site or email me I so I can talk of a price for this.
So the point was to show we can blend fuels and cut costs for miles traveled without giving up performances.
I use a CNG vacuum controlled regulator modified by me. We dump it in the air intake after the MAF and before the turbo inlet. I use an ECT from http://thesensorconnection.com and wire it in to turn on/off the CNG for safety. It runs about $200
The front end of the kit is very easy to install about 2 HR. Than a high pressure line inch or 6mm is run from the tank to the regulator.
I give up some trunk space for a CNG tank on a Jetta the trunk on this TDI I use 2 small test tank that fit in the spare tire space 1.5 GAL filled.
For the front end kit I see it in the $500 range
Used tanks can be found from $100 to $1000.
Someone but it to me this way if you pay $4.00 a GAL for Diesel and get 40 MPG so for 60 miles it was $6.00 and for me with CNG blend it cost ( using $1.00 a GAL for CNG) it cost $3.20 to do the same 60 miles that is a reduction of in half of fuel costs. But when you put the home fueling station in the math I pay .40 cents a GAL of CNG at home. It is now better I need someone to check this math is it 50% or 100% reduction ??
Bob Mann
CNGVW is offline  
Old May 22nd, 2012, 16:05   #8
Lug_Nut
TDIClub Enthusiast
Pre-Forum Veteran Member
 
Lug_Nut's Avatar
 
Join Date: Jun 1998
Location: Sterling, Massachusetts. USA
Default

.51 gallons of diesel: 33422.8 BTU
1.2 gallons of CNG: 198,750 BTU
total BTU: 232,172.8
or the energy in 1.8 gallons of diesel.
60 miles on the energy in 1.8 gallons of diesel is 33.3 mpg.

Good work!
__________________
If the quantity of carbonic acid increases in geometric progression,
the augmentation of the temperature will increase nearly in arithmetic progression.

Svante Arrhenius 1896

Cogito ergo soy (I think, therefore: Biodiesel)
Lug_Nut is offline  
Old May 22nd, 2012, 18:28   #9
BKmetz
Administrator
 
BKmetz's Avatar
 
Join Date: Sep 1997
Location: Illinois
Fuel Economy: 50 MPG
Default

Lug_Nut, I think you need to recheck your BTU values.

The BTU value of #2 diesel per galloon is not fixed. It changes to from one delivery to the next depending on the crude it was refined from. It's more like a range from 124,000BTUs (winter blend) to 139,000 BTUs.

I would say the heating value of .51 gallon of diesel would be around 65,000BTUs.

CH4/CNG is 1000BTUs per SCF (Standard Cubic Foot= 1ft cubed at zero degrees centigrade at sea level). 1 therm of CH4 = 100,000BTUs. So 100 SCF = 1 therm.

To me, the GGE is misleading because one needs to know the pressure and temperature when filling the tank. To know how much CNG was used there needs to be a flow meter that measures SCF or therms used.

To use the known numbers, an A4 TDI returns 45 MPG on average. The average heat value of #2 diesel, is say around ~130,000BTUs/gallon. The energy needed to travel 60 miles at interstate speeds would be around ~200,000BTUs.

So, 200,000BTUs used - 65,000BTUs diesel = 135,000BTUs CNG used. So in my best guestimate, 135,000BTUs of CNG was used, or 1.35 therms or 135 SCF.

There is no magic here. It is simply substituting one fuel for another as the amount of energy needed/used to move the car does not change.

Someone else will have to crunch the numbers to determine the cost of the installation kit, home filling station, electricity used to run the home filling station, and the CNG used.

__________________
Brian, 2015 Passat SE TDI 6MT, 2014 Passat SE TDI 6MT sold back to VW on 1-3-18
Wifey, 2014 Passat SE 2.5

If ANYONE receives a PM/email from a TDIClub member shilling anything and they are NOT a registered vendor, please forward the PM/emails to me. To report spam, trolling, or any problem post, click the report post icon. (The icon in the actual problem post, not the one in my sig. The idiots know who they are... )

Last edited by BKmetz; May 22nd, 2012 at 19:46. Reason: edited for clarification
BKmetz is offline  
Old May 22nd, 2012, 19:14   #10
thebigarniedog
Master of the Obvious
 
thebigarniedog's Avatar
 
Join Date: Oct 2007
Location: Fail Command (Central Ohio)
Default

Quote:
Originally Posted by BKmetz View Post
.....
Someone else will have to crunch the numbers to determine the cost of the installation kit, home filling station, electricity used to run the home filling station, and the CNG used.


I got this ......


__________________
When interviewed about why no diesel for the new F150, Ford responded to effect that diesel makes no sense in the 1/2 ton market. That brilliance should be repeated in every Ram 1500 eco-diesel commercial.

OCD TDICLUB MEMBER # 1
thebigarniedog is offline  
Old May 22nd, 2012, 20:31   #11
RWHP
Newbie
 
Join Date: May 2012
Location: Boston
Default

Quote:
Originally Posted by BKmetz View Post
Lug_Nut, I think you need to recheck your BTU values.

The BTU value of #2 diesel per galloon is not fixed. It changes to from one delivery to the next depending on the crude it was refined from. It's more like a range from 124,000BTUs (winter blend) to 139,000 BTUs.

I would say the heating value of .51 gallon of diesel would be around 65,000BTUs.

CH4/CNG is 1000BTUs per SCF (Standard Cubic Foot= 1ft cubed at zero degrees centigrade at sea level). 1 therm of CH4 = 100,000BTUs. So 100 SCF = 1 therm.

To me, the GGE is misleading because one needs to know the pressure and temperature when filling the tank. To know how much CNG was used there needs to be a flow meter that measures SCF or therms used.

To use the known numbers, an A4 TDI returns 45 MPG on average. The average heat value of #2 diesel, is say around ~130,000BTUs/gallon. The energy needed to travel 60 miles at interstate speeds would be around ~200,000BTUs.

So, 200,000BTUs used - 65,000BTUs diesel = 135,000BTUs CNG used. So in my best guestimate, 135,000BTUs of CNG was used, or 1.35 therms or 135 SCF.

There is no magic here. It is simply substituting one fuel for another as the amount of energy needed/used to move the car does not change.

Someone else will have to crunch the numbers to determine the cost of the installation kit, home filling station, electricity used to run the home filling station, and the CNG used.

Why even say that....shouldn't you be supporting the alternative fuel being as you are the administrator of the alternative fuel board? I think its pretty amazing that you may only have to visit the pump for fuel once a month. I've looked into the conversion and every way I work it out, it pays for itself in a year..all of the above factors included. I might try it out over the next few months on my 2000.
RWHP is offline  
Old May 22nd, 2012, 20:43   #12
CNGVW
 
Join Date: Sep 2009
Location: Bob Mann Auto, 111 High St, Pembroke MA 02359
Fuel Economy: Built a 2002 TDI Jetta that got 120 mpg of diesel using a CNG blend.
Default

CH4/CNG is 1000BTUs per SCF (Standard Cubic Foot= 1ft cubed at zero degrees centigrade at sea level). 1 therm of CH4 = 100,000BTUs. So 100 SCF = 1 therm. The true number for CNG is 114,118.8 BTUs =1.14 Therms here in the North East
Below is a good link for CNG infomation.
https://docs.google.com/document/d/1...MQ/edit?pli=1#
Just to clear up how the test was run filled up the tank with Diesel till it dripped out the fill rim. Drove next door to a Public CNG filling station and filled tanks with CNG the dispenser read out in GAL.
Drove it on some stop and go roads and then highways at 75-80 MPH to location then used the same return route and same fuel stops to top off.
There is no magic here it just shows if you can control the blend fuel and it is cheap and works with the diesel seamlessly .You can drive your cost per mile for fuel down.
This is nothing new to diesel trucks just to TDIs here.
You are more than welcome to drive the car and test it just give me a call 781-588-3968.
Bob Mann
CNGVW is offline  
Old May 23rd, 2012, 05:48   #13
Abacus
That helpful B4 guy
 
Abacus's Avatar
 
Join Date: Nov 2007
Location: Nobleboro, Maine
Fuel Economy: And the miles just keep ticking away
Default

Bob: thanks for posting this, but...personally, I would like to see a longer test since 60 miles isn't long enough to reach a reasonable conclusion.

As with any scientific procedure, repeatability is key to withstanding scrutiny.

Not trying to douse any fires here since I am interested in the process, but if you have over 1,000 miles on this system, why are you only posting the results from a 60 mile stretch? Can you give us a longer run and post the results? Thanks.

Quote:
60 Miles round trip used .51 Gal of Diesel and 1.2 GAL (GGE) of CNG yes I have the slips.
....
I have over 1000 miles on this test system no codes just works.
__________________
'97 B4: 453,000 miles Malone 3, PP520's, Stage 2 cam, SBC3, ARP studs, 2 1/4" exhaust, 2.5" Cat, no mufflers or EGR.
'96 B4V: 356,000 miles Malone 2+, PP520's, 6 speed, 02J short shifter, E-Codes, G60 brakes, Evo plate, DMF, stainless exhaust, heated leathers, cold weather package
BUG*PWR 2013 Award Winner
Abacus is offline  
Old May 23rd, 2012, 07:01   #14
cevans
TDIClub Enthusiast
TDI Parts Ninja Vendor
w/Business number
 
cevans's Avatar
 
Join Date: Sep 2002
Location: Hingham, MA
Default

Quote:
Originally Posted by BKmetz View Post
There is no magic here. It is simply substituting one fuel for another as the amount of energy needed/used to move the car does not change.

Someone else will have to crunch the numbers to determine the cost of the installation kit, home filling station, electricity used to run the home filling station, and the CNG used.

Exactly, the "fuel economy" is besides the point in this situation since CNG and diesel are different fuels, BTUs are also a bit besides the point as all BTUs aren't created equal when it comes to using them. For practical purposes it is cost per mile that is important.

If CNG can lower your cost per mile (by half), this concept works. Then you need to see where the break-even point is. Firstly of the "conversion" kit - and if necessary the home filling.
__________________
IDParts.com - IDParts.com Vendor Thread - The IDParts Blog - IDParts YouTube Channel
My Diesel "Addiction": '17 Canyon 2.8L DMax, '11 R350 BT, '06 E320 CDI // Past: 15' Ram ED, '13 NMS, '10 JSW, '10 Jetta Sedan, '07 R320 CDI, '03 Wagon, '00 Golf 2-Dr, '00 NB (Yellow :-)
Stop Hunting for Torque Specs - Get A Free IDParts Torque Spec Poster Today!

Last edited by cevans; May 23rd, 2012 at 07:03.
cevans is offline  
Old May 23rd, 2012, 07:54   #15
CNGVW
 
Join Date: Sep 2009
Location: Bob Mann Auto, 111 High St, Pembroke MA 02359
Fuel Economy: Built a 2002 TDI Jetta that got 120 mpg of diesel using a CNG blend.
Default

Quote:
Originally Posted by Abacus View Post
Bob: thanks for posting this, but...personally, I would like to see a longer test since 60 miles isn't long enough to reach a reasonable conclusion.

As with any scientific procedure, repeatability is key to withstanding scrutiny.

Not trying to douse any fires here since I am interested in the process, but if you have over 1,000 miles on this system, why are you only posting the results from a 60 mile stretch? Can you give us a longer run and post the results? Thanks.

[/SIZE][/FONT]
I have been testing the system to make shore it was a turnkey setup and worked out some bugs. I have plans to redo the MPG test in a more controlled environment. I will be making it a loaner to those that wish to drive it.
Bob Mann
CNGVW is offline  
Closed Thread


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
CNG + Diesel dunlin182 Alternative Diesel Fuels (Biodiesel, WVO, SVO, BTL, GTL etc) 18 March 5th, 2009 17:21
Why Ford's 65 mpg diesel won't join the VW TDI in the U.S. Dana Bartholomew Non VW Group Diesels 7 September 30th, 2008 16:41
Buy a diesel Dodge or Jeep, get all your diesel for $2.99/gal McBrew Fuels & Lubricants 41 May 21st, 2008 17:50
Diesel+CNG+Water/methanol AnArKey TDI Power Enhancements 1 December 7th, 2005 13:56
Diesel sulpher change over, diesel to go to $5/gal geez Fuels & Lubricants 11 November 2nd, 2005 16:40


All times are GMT -7. The time now is 09:15.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright - TDIClub Online LTD - 2017
Contact Us | Privacy Statement | Forum Rules | Disclaimer
TDIClub Online Ltd (TDIClub.com) is not affiliated with the VWoA or VWAG and is supported by contributions from viewers like you.
1996 - 2017, All Rights Reserved
Page generated in 0.19105 seconds with 11 queries
[Output: 137.52 Kb. compressed to 116.09 Kb. by saving 21.42 Kb. (15.58%)]