Go Back   EcoModder Forum > EcoModding > EcoModding Central
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 09-20-2013, 02:03 PM   #1 (permalink)
Aero Deshi
 
ChazInMT's Avatar
 
Join Date: Jan 2010
Location: Vero Beach, FL
Posts: 1,065

MagMetalCivic - '04 Honda Civic Sedan EX
Last 3: 34.25 mpg (US)
Thanks: 430
Thanked 669 Times in 358 Posts
Question Need help on the Math

Literally....one of my weaker aspects is math. Here's a puzzler for you, and one I'm sure others have encountered.

When approaching the state line the other day, my tank was nearing empty. My GasBuddy App....great app for the droid btw to find the gas prices at stations in any given area....showed my greener pastures 20 miles ahead, however, my Empty light and mileage on current tank said there was a real chance I may not get another 20 miles. Not really wanting to run out of gas, at all, but not wanting to pay 25¢ per gallon more for a full tank, I did the ecomodder nightmare and put in just 1 gallon instead of filling up so I could accurately track my mileage.

So when I filled up after the 20 miles, how do I enter my miles & gallons on the fuel log?

I went 432 miles, put in a gallon, drove another 20, there was 452 miles on Trip-O-Meter when I filled up putting 12.3 gallons in the sled. My tank capacity is 13.2 gallons if it means anything.

Any advice?

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 09-20-2013, 02:10 PM   #2 (permalink)
Eco-ventor
 
jakobnev's Avatar
 
Join Date: Oct 2010
Location: sweden
Posts: 1,645

Princess - '92 Mazda MX-3 GS
House of Tudor
Team Mazda
90 day: 53.54 mpg (US)

Shirubāarō (*´ω`*) - '05 Toyota Prius Executive
Team Toyota
90 day: 54.88 mpg (US)

Blue Thunder - '20 Hyundai IONIQ Trend PHEV
Team Hyundai
Plug-in Hybrids
90 day: 194.72 mpg (US)
Thanks: 76
Thanked 709 Times in 450 Posts
Send a message via MSN to jakobnev
452 miles and 13.3 gallons.
__________________




2016: 128.75L for 1875.00km => 6.87L/100km (34.3MPG US)
2017: 209.14L for 4244.00km => 4.93L/100km (47.7MPG US)
  Reply With Quote
Old 09-20-2013, 02:22 PM   #3 (permalink)
Aero Deshi
 
ChazInMT's Avatar
 
Join Date: Jan 2010
Location: Vero Beach, FL
Posts: 1,065

MagMetalCivic - '04 Honda Civic Sedan EX
Last 3: 34.25 mpg (US)
Thanks: 430
Thanked 669 Times in 358 Posts
That's what I figured, then I freak my self out with this thought.

I get close to 40mpg say, so when I put in the 1 gallon and go 20 miles, I figure I burned about 1/2 gallon of gas. So when I put in 12.3, and add the half gallon I used, that would be 12.8. I didn't use the whole gallon of gas.

Sorry, but when you give an answer here, in order to get it sorted in my over thinking skull, I'm going to need an explanation for the logic of how you arrived at your answer.
  Reply With Quote
Old 09-20-2013, 02:28 PM   #4 (permalink)
The Dirty330 Modder
 
Gealii's Avatar
 
Join Date: Dec 2011
Location: North East Ohio, USA
Posts: 642

CruzeRS - '15 Chevy Cruze LT RS
90 day: 41.29 mpg (US)
Thanks: 10
Thanked 67 Times in 59 Posts
Quote:
Originally Posted by ChazInMT View Post
That's what I figured, then I freak my self out with this thought.

I get close to 40mpg say, so when I put in the 1 gallon and go 20 miles, I figure I burned about 1/2 gallon of gas. So when I put in 12.3, and add the half gallon I used, that would be 12.8. I didn't use the whole gallon of gas.

Sorry, but when you give an answer here, in order to get it sorted in my over thinking skull, I'm going to need an explanation for the logic of how you arrived at your answer.
all you do is not reset your trip meter. when you go to fill up you add the gallons filled from both stops together then just calculate your mpgs like normal
__________________



"The only real mistake is the one from which we learn nothing."
- Henry Ford
  Reply With Quote
Old 09-20-2013, 03:20 PM   #5 (permalink)
Eco-ventor
 
jakobnev's Avatar
 
Join Date: Oct 2010
Location: sweden
Posts: 1,645

Princess - '92 Mazda MX-3 GS
House of Tudor
Team Mazda
90 day: 53.54 mpg (US)

Shirubāarō (*´ω`*) - '05 Toyota Prius Executive
Team Toyota
90 day: 54.88 mpg (US)

Blue Thunder - '20 Hyundai IONIQ Trend PHEV
Team Hyundai
Plug-in Hybrids
90 day: 194.72 mpg (US)
Thanks: 76
Thanked 709 Times in 450 Posts
Send a message via MSN to jakobnev
Quote:
I figure I burned about 1/2 gallon of gas.
I'll just leave you with this to ponder on: Where did the other 1/2 gallon go?
__________________




2016: 128.75L for 1875.00km => 6.87L/100km (34.3MPG US)
2017: 209.14L for 4244.00km => 4.93L/100km (47.7MPG US)
  Reply With Quote
Old 09-20-2013, 10:36 PM   #6 (permalink)
EcoModding Lurker
 
Join Date: Apr 2013
Location: Nj
Posts: 48

wrx - '02 subaru impreza wrx wagon
90 day: 33.81 mpg (US)

Leg - '05 Subaru Legacy 2.5i
Thanks: 2
Thanked 2 Times in 2 Posts
Quote:
Originally Posted by ChazInMT View Post
That's what I figured, then I freak my self out with this thought.

I get close to 40mpg say, so when I put in the 1 gallon and go 20 miles, I figure I burned about 1/2 gallon of gas. So when I put in 12.3, and add the half gallon I used, that would be 12.8. I didn't use the whole gallon of gas.

Sorry, but when you give an answer here, in order to get it sorted in my over thinking skull, I'm going to need an explanation for the logic of how you arrived at your answer.
Your correct here, though go with your average posted 35.3 mpg so 20miles/35.3 miles/gallon=.57 g then 12.9 g

however the problem is that since you drove farther then the last time you filled up you used more then 12.3g. plus another .57g haha even if you fill up at the same point every time there is always going to be a high tolerance without actively flowing the volume used.
  Reply With Quote
Old 09-20-2013, 11:06 PM   #7 (permalink)
Master EcoModder
 
Join Date: Sep 2009
Posts: 5,927
Thanks: 877
Thanked 2,024 Times in 1,304 Posts
I got 15 gallons of gas @ $3.199 a month ago. I filled the motorcycle until the 5 gallon can was empty then logged the mileage. One can was perfect, the whole can for the last refill.
The other can was not quite enough so I went to the station and topped it off. Every time I refilled I wrote the mileage down on a piece of masking tape on the cabinet in the garage. When the can was empty I knew the mileage for 5 gallons, which was more than the tank capacity.
I would just consider the trip odometer. When you refilled and reset the trip meter, that is the point where you calculate the mileage from one trip reset to another, unless you just record odometer mileage when you refill.
Since you waited until you completely filled the tank to reset the trip, that is where the calculation occurs. 1 gallon earler and the rest when you got to the station with a better price. The total of both fills is your refill amount since that is when you reset the trip meter.

regards
Mech
  Reply With Quote
Old 09-20-2013, 11:41 PM   #8 (permalink)
Human Environmentalist
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 12,758

Acura TSX - '06 Acura TSX
90 day: 24.19 mpg (US)

Lafawnda - CBR600 - '01 Honda CBR600 F4i
90 day: 47.32 mpg (US)

Big Yeller - Dodge/Cummins - '98 Dodge Ram 2500 base
90 day: 21.82 mpg (US)

Chevy ZR-2 - '03 Chevrolet S10 ZR2
90 day: 17.14 mpg (US)

Model Y - '24 Tesla Y LR AWD

Pacifica Hybrid - '21 Chrysler Pacifica Hybrid
90 day: 57.45 mpg (US)
Thanks: 4,319
Thanked 4,472 Times in 3,437 Posts
I would have pushed on for the cheaper station without stopping. However, if you do the math, you will see that you consumed 13.3 gallons in your 452 mile trip. Your tank only holds 13.2 gallons, so you would have run out of fuel about 3 miles away from the cheaper station... you would have seen me jogging on the highway with an gas can. Clearly you made the right choice.

I've stopped to put a gallon in at an expensive station before, not knowing if I could make it to the cheaper stations. With my UG now installed and calibrated, I can push things a lot more comfortably. My fuel light comes on when there is well over a hundred miles left on the tank!
__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
Old 09-21-2013, 12:07 AM   #9 (permalink)
Not Doug
 
Xist's Avatar
 
Join Date: Jun 2012
Location: Show Low, AZ
Posts: 12,232

Chorizo - '00 Honda Civic HX, baby! :D
90 day: 35.35 mpg (US)

Mid-Life Crisis Fighter - '99 Honda Accord LX
90 day: 34.2 mpg (US)

Gramps - '04 Toyota Camry LE
90 day: 35.39 mpg (US)

Don't hit me bro - '05 Toyota Camry LE
90 day: 30.49 mpg (US)
Thanks: 7,254
Thanked 2,231 Times in 1,721 Posts
Quote:
Originally Posted by redpoint5 View Post
I would have pushed on for the cheaper station without stopping. However, if you do the math, you will see that you consumed 13.3 gallons in your 452 mile trip. Your tank only holds 13.2 gallons, so you would have run out of fuel about 3 miles away from the cheaper station... you would have seen me jogging on the highway with an gas can. Clearly you made the right choice.

I've stopped to put a gallon in at an expensive station before, not knowing if I could make it to the cheaper stations. With my UG now installed and calibrated, I can push things a lot more comfortably. My fuel light comes on when there is well over a hundred miles left on the tank!
I was wondering about the math!

My low-fuel light does not come on...

I learned to not wait.
  Reply With Quote
Old 09-21-2013, 02:38 PM   #10 (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
add up all the miles, add up all the fuel.
then do the calculus.

__________________
Strayed to the Dark Diesel Side

  Reply With Quote
Reply  Post New Thread


Tags
mileage calculation, partial tank fill





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