Go Back   EcoModder Forum > EcoModding > General Efficiency Discussion
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 07-18-2009, 02:00 AM   #1 (permalink)
Moderate your Moderation.
 
Join Date: Nov 2008
Location: Troy, Pa.
Posts: 8,919

Pasta - '96 Volkswagen Passat TDi
90 day: 45.22 mpg (US)
Thanks: 1,369
Thanked 430 Times in 353 Posts
Check my math?

I was thinking about the basic fuel consumption figures in the OM636 Manual I have... the max figure is 215g/HPh (Grams per HorsePower hour).

I wanted to figure out how much fuel (in gallons) it would take to make 1 HP for 1 hour, using this figure as the basis...

So I found that diesel fuel has mass of 3217.6 grams per gallon.

In order to find out how many gallons of fuel I should use to make 1 HP for 1 hour (1 HPh),

215/3217.6 = 0.0668199901

Is that right?

Reversing the equation gives me:

3217.6/215 = 14.9655814, which I take as being 1/15 of one gallon per HPh. Dividing 1/15 out gives me:

1 / 15 = 0.0666666667, approximately the same answer as above... so which way is the correct way to come about the answer?

(The first answer is "It doesn't matter, as long as it's right." But this doesn't hold true in math. If you got the right answer, by the wrong equation, it's still the wrong answer. You can't "stumble on" an answer in math, and I want to know the correct way to do it.)

__________________
"ʞɐǝɹɟ ɐ ǝɹ,noʎ uǝɥʍ 'ʇı ʇ,usı 'ʎlǝuol s,ʇı"

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 07-18-2009, 03:50 AM   #2 (permalink)
Master EcoModder
 
Join Date: Jan 2008
Location: Sacramento, CA
Posts: 400
Thanks: 33
Thanked 138 Times in 102 Posts
Christ,
As long as your known numbers are correct, use your units to verify the equation.

215g/1 hph x 1 gal/3217.6g = .0668gal/1hph which is your original solution.

I guess we have to assume that the 215g/hph figure includes whatever the nominal efficiency is for the engine.
JJ
  Reply With Quote
Old 07-18-2009, 09:21 PM   #3 (permalink)
Moderate your Moderation.
 
Join Date: Nov 2008
Location: Troy, Pa.
Posts: 8,919

Pasta - '96 Volkswagen Passat TDi
90 day: 45.22 mpg (US)
Thanks: 1,369
Thanked 430 Times in 353 Posts
215g/hph is the highest figure in the manual for fuel consumption. It's all I've got to go on.
__________________
"ʞɐǝɹɟ ɐ ǝɹ,noʎ uǝɥʍ 'ʇı ʇ,usı 'ʎlǝuol s,ʇı"

  Reply With Quote
Old 07-22-2009, 12:01 PM   #4 (permalink)
EcoModding Lurker
 
Join Date: Mar 2009
Location: NC
Posts: 8
Thanks: 0
Thanked 1 Time in 1 Post
Bean counter$ !

Quote:
Originally Posted by Christ View Post
215g/hph is the highest figure in the manual for fuel consumption. It's all I've got to go on.
My comment on the subject at hand is not the issue here. But I HAVE to say the line on bean counters is right on! The bean counters set GM up for a disaster ... beginning with R. Nader & the Corvair fiasco ... all the way to misreading the Toyota and Datsun invasion. Now, GM stands for Government Motors...and we'll see ( like who gets the next "bail-out" from the gov't? The gov't?).
We live in intere$ting times !!!
  Reply With Quote
Old 07-22-2009, 01:17 PM   #5 (permalink)
Moderate your Moderation.
 
Join Date: Nov 2008
Location: Troy, Pa.
Posts: 8,919

Pasta - '96 Volkswagen Passat TDi
90 day: 45.22 mpg (US)
Thanks: 1,369
Thanked 430 Times in 353 Posts
Quote:
Originally Posted by chembustion View Post
My comment on the subject at hand is not the issue here. But I HAVE to say the line on bean counters is right on! The bean counters set GM up for a disaster ... beginning with R. Nader & the Corvair fiasco ... all the way to misreading the Toyota and Datsun invasion. Now, GM stands for Government Motors...and we'll see ( like who gets the next "bail-out" from the gov't? The gov't?).
We live in intere$ting times !!!
Tasdrouille said it, I just quoted it. Thanks anyway.

__________________
"ʞɐǝɹɟ ɐ ǝɹ,noʎ uǝɥʍ 'ʇı ʇ,usı 'ʎlǝuol s,ʇı"

  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Longtime Lurker Looking for Miles ZX40 Electric Micro van mods & information rmay635703 Fossil Fuel Free 49 07-06-2014 10:27 PM
Super efficient fridge - need math advice Cd Saving@Home 17 07-12-2009 10:16 AM
HELP! Check engine light - Loss of power bennelson Off-Topic Tech 28 07-07-2009 06:13 PM
volumetric efficiency and math bgd73 General Efficiency Discussion 1 06-27-2009 01:33 PM
Stimulus Check bah! Hand out scangauges instead. rsx2002 EcoModding Central 24 07-17-2008 10:28 AM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com