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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 03-11-2020, 07:08 PM   #1 (permalink)
EcoModding Newb
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 7,896

Acura TSX - '06 Acura TSX
90 day: 25.55 mpg (US)

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

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

Prius Plug-in - '12 Toyota Prius Plug-in
90 day: 57.64 mpg (US)

Mazda CX-5 - '17 Mazda CX-5 Touring
90 day: 23.74 mpg (US)
Thanks: 2,605
Thanked 3,109 Times in 2,314 Posts
Typical Energy Expenditure %

Just curious if there is any ballpark figure out there about what percent of motive energy is spent for the average vehicle to:

Accelerate
Overcome rolling resistance
Overcome aero resistance

By motive energy, I mean not factoring in engine (in)efficiency, drivetrain losses, accessories, etc.

My guess is that acceleration accounts for less than 5% of motive energy as an average, perhaps much less than that even. Obviously this figure would be higher for those that spend more time in stop and go traffic, and less for steady state highway cruising. As an average though, what do you think it would be?

__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
The Following User Says Thank You to redpoint5 For This Useful Post:
aerohead (03-18-2020)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 03-11-2020, 08:46 PM   #2 (permalink)
EV convert
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 8,662

Sub - '84 Chevy Diesel Suburban C10
SUV
90 day: 19.5 mpg (US)

camaro - '85 Chevy Camaro Z28

Riot - '03 Kia Rio POS
Team Hyundai
90 day: 30.21 mpg (US)

Bug - '01 VW Beetle GLSturbo
90 day: 26.43 mpg (US)

Sub2500 - '86 GMC Suburban C2500
90 day: 11.95 mpg (US)

Snow flake - '11 Nissan Leaf SL
SUV
90 day: 140.34 mpg (US)
Thanks: 210
Thanked 2,858 Times in 2,235 Posts
There's highway, city and mixed tables for this.

I think there is a rolling resistance and drag calculator over on camaroz28 dot com.
__________________
1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
2011 leaf SL, white, portable 240v CHAdeMO, trailer hitch, new batt as of 2014.

Last edited by oil pan 4; 03-11-2020 at 10:20 PM..
  Reply With Quote
Old 03-13-2020, 07:06 PM   #3 (permalink)
Master EcoModder
 
Join Date: Jan 2012
Location: United States
Posts: 1,435

spyder2 - '00 Toyota MR2 Spyder
Thanks: 89
Thanked 267 Times in 204 Posts
You can roughly estimate this. For example with my FR-S, I was getting about 18-20mpg? while looking for parking in San Francisco. I recall estimating that rolling at 25mph with pulse and glide was getting me around 90mpg, and almost all of that consumption would be rolling resistance.

Engine on P&G that number drops to the 40s I think. But the average speed is really much closer to 10mph, so it's like 30mpg.

So I think it's fair to say acceleration is taking close to 40% of the energy in that stop and go scenario.

For long freeway drives, probably 80% air resistance?

Last edited by serialk11r; 03-13-2020 at 07:12 PM..
  Reply With Quote
Old 03-13-2020, 07:47 PM   #4 (permalink)
Tyrant-at-large
 
Vman455's Avatar
 
Join Date: Feb 2012
Location: Champaign, IL
Posts: 1,606

Little Red - retired - '05 Honda Civic EX
90 day: 49.03 mpg (US)

Pope Pious the Prius - '13 Toyota Prius Two
Team Toyota
SUV
90 day: 58.55 mpg (US)
Thanks: 174
Thanked 1,386 Times in 727 Posts
Quote:
Originally Posted by serialk11r View Post
For long freeway drives, probably 80% air resistance?
Not quite that much for the typical car, I suspect, but some bro-trucks might be more. In a Prius L Eco, at 70 mph you're using ~64% of the energy to overcome aerodynamic drag and the rest for rolling resistance. A 2020 Ram in its lowest drag trim, Cd = 0.36, is around 74% to aero drag at the same speed. At Cd = 0.45, the same truck is 78% to aero drag.

But the total resistive force acting on the last truck example, and therefore the work required to move it a given distance at a constant velocity, is two and a half times as much as the Prius. That puts things in perspective.

__________________

  Reply With Quote
Old 03-13-2020, 09:11 PM   #5 (permalink)
EcoModding Newb
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 7,896

Acura TSX - '06 Acura TSX
90 day: 25.55 mpg (US)

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

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

Prius Plug-in - '12 Toyota Prius Plug-in
90 day: 57.64 mpg (US)

Mazda CX-5 - '17 Mazda CX-5 Touring
90 day: 23.74 mpg (US)
Thanks: 2,605
Thanked 3,109 Times in 2,314 Posts
Right, the answer for an individual use case and vehicle is, it depends on the individual use case and vehicle. Just curious if this has been estimated across the entire US fleet? I think even 5% for acceleration alone is high.

One way to roughly calculate this on an individual basis would be to keep track of how much electricity a hybrid or EV regens over time.
__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
Old 03-15-2020, 08:41 PM   #6 (permalink)
Master EcoModder
 
Join Date: Jan 2012
Location: United States
Posts: 1,435

spyder2 - '00 Toyota MR2 Spyder
Thanks: 89
Thanked 267 Times in 204 Posts
Ah you're right, I overestimated drag vs. rolling resistance.

FWIW, Enterprise had a discount a few months ago on Tesla rentals, and I drove a Model S 70D up a fairly steep hill. The battery drained very very fast going up, with the miles remaining estimate going down something like 20 miles for only 4 miles covered, and then on the way down it barely gained any miles back.

Since the speeds involved were low, that tells you rolling resistance is still quite significant. That said, a permanent magnet motor powered car would probably do a little better on the same run.
  Reply With Quote
Old 03-17-2020, 06:27 AM   #7 (permalink)
Eco-ventor
 
jakobnev's Avatar
 
Join Date: Oct 2010
Location: sweden
Posts: 1,255

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

Shirubāarō (*ω`*) - '05 Toyota Prius Executive
Thanks: 53
Thanked 454 Times in 285 Posts
Send a message via MSN to jakobnev
What does it mean to spend energy on acceleration? When you have accelerated you still have that energy in kinetic form. Only after losing the speed do you know where it went. (rolling, aero, braking etc)
__________________




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 03-17-2020, 09:34 AM   #8 (permalink)
In the fasting lane
 
RedDevil's Avatar
 
Join Date: Dec 2012
Location: Nieuwegein, the Netherlands
Posts: 3,718

Red Devil - '11 Honda Insight Elegance
Team Honda
90 day: 53.47 mpg (US)

It - '09 Hyundai I10 Active Cool
Team Hyundai
90 day: 28.5 mpg (US)
Thanks: 1,494
Thanked 2,037 Times in 1,310 Posts
Or two black stripes on the pavement
__________________
2011 Honda Insight + HID, LEDs, tiny PV panel, extra brake pad return springs, neutral wheel alignment, 44/42 PSI (air), PHEV light (inop), tightened wheel nut.
lifetime FE over 0.16 Gmeter or 0.1 Mmile.



Most people are in the longest queue.
  Reply With Quote
Old 03-17-2020, 12:34 PM   #9 (permalink)
EcoModding Newb
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 7,896

Acura TSX - '06 Acura TSX
90 day: 25.55 mpg (US)

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

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

Prius Plug-in - '12 Toyota Prius Plug-in
90 day: 57.64 mpg (US)

Mazda CX-5 - '17 Mazda CX-5 Touring
90 day: 23.74 mpg (US)
Thanks: 2,605
Thanked 3,109 Times in 2,314 Posts
Quote:
Originally Posted by jakobnev View Post
What does it mean to spend energy on acceleration? When you have accelerated you still have that energy in kinetic form. Only after losing the speed do you know where it went. (rolling, aero, braking etc)
Exactly. The energy not accounted for by rolling or aero resistance; ie braking.
__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
Old 03-17-2020, 04:57 PM   #10 (permalink)
Master EcoModder
 
Join Date: Feb 2010
Location: Elmira, NY
Posts: 1,671
Thanks: 283
Thanked 294 Times in 246 Posts
If you drag out your physics text book or other technical articles there are formulas to calculate energy required in each case. The mass of the vehicle is listed on the vehicle or there are weigh stations. Drag is most easily measured in a coast down test.

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com