View Single Post
Old 12-08-2008, 12:51 PM   #1 (permalink)
Batman Junior
MetroMPG's Avatar
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 21,238

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 52.8 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
90 day: 73.57 mpg (US)

Fancy Metro - '14 Mitsubishi Mirage top spec
90 day: 55.99 mpg (US)
Thanks: 2,988
Thanked 5,877 Times in 3,046 Posts
Arrow Online tool: shows aerodynamic drag, rolling resistance, power required & est. MPG

Aerodynamic & rolling resistance calculator -

Back in the day, krousdb made a spreadsheet to calculate aero & rolling resistance forces against his del Sol, their respective power requirements, and effect on fuel consumption at various speeds.

I've ported/expanded the spreadsheet into an online tool which asks you to enter or accept default values for...
- vehicle weight
- Crr (coefficient of rolling resistance - .008 represents a low rolling resistance tire on a smooth surface - see Wikipedia for other sample values)
- Cd
- Frontal Area
- Fuel energy density (in Watt hours / US gallon)
- Engine efficiency
- Air density (rho)
... and it spits out a table showing resistance force values, estimated power requirements and fuel consumption across a range of speeds.

It's online at EM here: Aerodynamic & rolling resistance calculator -

It's not perfect (e.g. engine efficiency changes with load in real life, but remains fixed at the value you supply for all speeds in the calculations for fuel consumption).

Discussion, questions, suggestions welcome.

Latest mods test: 15 mods = 15% MPG improvement: A-B test, 2007 Honda Civic 1.8L, 5-speed
Ecodriving test:
Manual vs. automatic transmission MPG showdown: Nissan Micra 1.6L

has launched a forum for the efficient new Mitsubishi Mirage - fuel efficiency info for Geo Metro owners - electric car conversion on a beer budget
  Reply With Quote
The Following 3 Users Say Thank You to MetroMPG For This Useful Post:
ausias (09-28-2011), CarterX27 (12-30-2012), herbivor (06-14-2016)