Go Back   EcoModder Forum > EcoModding > Success Stories
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 11-04-2013, 09:48 AM   #301 (permalink)
Master EcoModder
 
euromodder's Avatar
 
Join Date: Jul 2010
Location: Belgium
Posts: 4,683

The SCUD - '15 Fiat Scudo L2
Thanks: 178
Thanked 652 Times in 516 Posts
Quote:
Originally Posted by 320touring View Post
you starting a thread for the car?
I know, I know I should ...

Quote:
I for one would be intrigued to see what the CNG setup looks like compared to LPG
  • CNG is stored as a gas despite the 200 bar / 2900 psi tank pressure - LPG is stored as a liquid.
  • 2-stage pressure reduction system, the 2nd stage using variable output pressure based on the engine's demand and is heated by the engine coolant.
  • large, voluminous cylindrical tanks for CNG rather than space-saving donut type tanks for LPG.
  • VW have increased the compression and fitted hardened valves + seats, so no messing about with valve lube etc. like with LPG
    (valve lubing is often needed on retrofitted CNG cars though)
  • Monovalent car, so the driver can't select which fuel to use (which you can in LPG or CNG-retrofitted cars) - it runs on CNG until the tanks are empty.

__________________
Strayed to the Dark Diesel Side

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 11-04-2013, 01:01 PM   #302 (permalink)
Master EcoModder
 
Join Date: Jun 2010
Location: scotland
Posts: 1,429

The Mistress - '88 Bmw 320i Touring SE
Team m8
Last 3: 27.17 mpg (US)

Germany Beadle - '91 Mercedes 300td (estate, N/A)
90 day: 24.63 mpg (US)

The Bloodylingo - '05 Citroen Berlingo Multispace Desire
90 day: 39.77 mpg (US)

Shanner Scaab - '03 Saab 9-5 estate Vector
90 day: 26.19 mpg (US)

Clio 182 - '05 Renault Clio RS 182 182
90 day: 31.73 mpg (US)
Thanks: 89
Thanked 89 Times in 74 Posts
Quote:
Originally Posted by euromodder View Post
I know, I know I should ...
Consider thyself admonished!
Quote:
[*]CNG is stored as a gas despite the 200 bar / 2900 psi tank pressure - LPG is stored as a liquid.
Hmm- thats some pressure-similar to a modern common rail diesel- guess it explains the tanks!

Quote:
[*]2-stage pressure reduction system, the 2nd stage using variable output pressure based on the engine's demand and is heated by the engine coolant.
Similar to a vapourisor on an LPG setup? except with pressure control as well. sounds good- inso far as it is load reactive

Quote:
[*]large, voluminous cylindrical tanks for CNG rather than space-saving donut type tanks for LPG.
How does that impact on the available space in the Up!? does it reside in the location usually reserved for the petrol tank?

Quote:
[*]VW have increased the compression and fitted hardened valves + seats, so no messing about with valve lube etc. like with LPG
(valve lubing is often needed on retrofitted CNG cars though)
so similar to LPG in that its a drier fuel than petrol, and some cars can suffer valve seat recession due to using it? Jaguars need valve lube for LPG, but the BMWs I have are happy without it

Interesting re the compression! does CNG have a higher RON rating, but lower calorific value?

Quote:
[*]Monovalent car, so the driver can't select which fuel to use (which you can in LPG or CNG-retrofitted cars) - it runs on CNG until the tanks are empty.
ah, so no handy "range extender" option then? I did like that about LPg


Cheers for the insight (ecomod punFTW!)
__________________
My Blog on cars- Fu'Gutty Cars
http://fuguttycars.wordpress.com/

US MPG for my Renault Clio 182


---------------------------------------------------
  Reply With Quote
Old 11-04-2013, 06:20 PM   #303 (permalink)
Master EcoModder
 
euromodder's Avatar
 
Join Date: Jul 2010
Location: Belgium
Posts: 4,683

The SCUD - '15 Fiat Scudo L2
Thanks: 178
Thanked 652 Times in 516 Posts
Quote:
Originally Posted by 320touring View Post
Consider thyself admonished!
Quote:
Similar to a vapourisor on an LPG setup?
Yes.

Quote:
How does that impact on the available space in the Up!? does it reside in the location usually reserved for the petrol tank?
The 2 gas tanks are underneath the car, one on either side of the rear axle.
The fuel tank is reduced to 10 liter / 2.6 US gal .
There's no well for a spare wheel - which I haven't been carrying for the last 3 years anyway. You do get a compressor and some fix-a-flat gooey ...
The trunk floor is mounted a few cm higher - and lacking the well.
The whole CNG system adds about 100kg - most of that is the weight of the tanks.


Quote:
so similar to LPG in that its a drier fuel than petrol, and some cars can suffer valve seat recession due to using it?
Yeah. CNG doesn't lube at all.

Quote:
Interesting re the compression! does CNG have a higher RON rating, but lower calorific value?
It's 130 RON.
Caloric value of the gas I use most often is low, below 10.

Quote:
ah, so no handy "range extender" option then? I did like that about LPg
After the gas is gone, there's only the 10 L petrol tank.
I chickened out at 9.5L recently.
Effectively giving a 528km combined range.

10L should be OK for some 200km, but as the car briefly uses petrol after tanking CNG (100 yards or so) you never really know how many km it has done on petrol.


VW wants you to replace the petrol every 6 months to keep it from going stale.
So the first 2 years, that's what I'll do

__________________
Strayed to the Dark Diesel Side

  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Cordless Electric Lawn Mowers Do Work! rgathright Saving@Home 21 12-09-2011 10:08 AM
From 15 to 23.75mpg in a 5500lb work truck JacobAziza EcoModding Central 21 12-04-2009 01:38 AM
Will this work for my metro thefirebuilds General Efficiency Discussion 4 12-27-2008 11:45 AM
Scangauge doesn't work lovemysan Instrumentation 2 09-01-2008 10:49 PM
Request for 'work in progres' thread Daox Forum News & Feedback 4 12-23-2007 10:03 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com