Go Back   EcoModder Forum > EcoModding > Fossil Fuel Free
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 03-16-2008, 11:31 PM   #1 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,527

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

MPGiata - '90 Mazda Miata
90 day: 54.46 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car Mirage - '14 Mitsubishi Mirage ES (base)
90 day: 62.14 mpg (US)
Thanks: 4,078
Thanked 6,976 Times in 3,612 Posts
Experiment: EV coastdown in gear vs. neutral (in the ForkenSwift)

After watching the video of shifting the clutchless transmission, I've had a few people ask me why I bother shifting to neutral to coast an EV. One would expect a complete lack of "engine" braking with an electric motor where the engine used to be. No?

Well, I've noticed that there does seem to be some drag from the motor (its brushes & bearings and drive end cooling fan being the culprits). It's not a lot, but I never tried to quantify it... until today.

So this afternoon I went out and did a very simple, and not entirely thorough test:

Coastdown from 20 km/h (indicated) in 1st gear vs. neutral.

First gear
- 58.8 m / 193 ft (average of 2 runs)

Neutral
- 70.4 m / 231 ft (average of 2 runs)

Difference
- 11.6 m / 38 ft, or 20%, or slightly more than 3 car lengths





Conditions: 1 degree C, cold car, calm winds, snow tires @ 55 psi, level road (to my eye). Oh, and the right front wheel bearing is toast. It's the source of most of the "road" noise you hear in the video in 2nd gear and higher. :-D

So I figure I'll keep popping it into neutral when I'm coasting up to stops & turns.



__________________
Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
Mitsu mods: 70 MPG in my ecomodded, dirt cheap, 3-cylinder Mirage.
Ecodriving test: Manual vs. automatic transmission MPG showdown



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 03-17-2008, 12:16 AM   #2 (permalink)
Master EcoModder
 
Peakster's Avatar
 
Join Date: Dec 2007
Location: Regina SK Canada
Posts: 407

Red Jeep Patriot - '07 Jeep Patriot
90 day: 25.14 mpg (US)

Beige Ford Ranger - '95 Ford Ranger XLE
Thanks: 0
Thanked 2 Times in 2 Posts
Wow, that's 11+ metres is pretty considerable.

The question I have is:
Doesn't the coasting in gear trickle some energy back into the batteries? Sort of like a radio controlled car.
  Reply With Quote
Old 03-17-2008, 12:16 AM   #3 (permalink)
EcoModding Apprentice
 
LUVMY02CREW's Avatar
 
Join Date: Jan 2008
Location: Mid TN
Posts: 152

TANK the fifth - '02 Chevrolet S10 Crew Cab 4x4 LS
90 day: 20.44 mpg (US)
Thanks: 4
Thanked 2 Times in 2 Posts
Very quiet video!

I don't think I could go that long without having the radio on or talking to myself

I've noticed more than a few times(no actual measuring yet) when I coast in gear(regular ole 2HI button on) it is definately a shorter ride. I've got an automatic, so I'm still kinda leary of doing this toooooo much and I try to make neutral coasts only when coming up to a stop where I know I will truly have to stop so I can ease back into D without engine RPM's getting loopy on me.
__________________
  Reply With Quote
Old 03-17-2008, 12:20 AM   #4 (permalink)
Awesomeness personified
 
AndrewJ's Avatar
 
Join Date: Dec 2007
Location: Columbia, MO
Posts: 642

Harold - '94 Honda Civic CX
90 day: 54.51 mpg (US)

Margot - '08 Surly Big Dummy
Thanks: 0
Thanked 28 Times in 18 Posts
Send a message via AIM to AndrewJ
Nice!

It's funny to watch that vid and notice that I'm "driving-along" by noting when I'd be throwing 'er in neutral.
These new driving habits die hard.
__________________
"I got 350 heads on a 305 engine. I get 10 miles to the gallon. I ain't got no good intentions." - The Drive By Truckers.

  Reply With Quote
Old 03-17-2008, 01:03 AM   #5 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,527

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

MPGiata - '90 Mazda Miata
90 day: 54.46 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car Mirage - '14 Mitsubishi Mirage ES (base)
90 day: 62.14 mpg (US)
Thanks: 4,078
Thanked 6,976 Times in 3,612 Posts
Quote:
Originally Posted by LUVMY02CREW View Post
I don't think I could go that long without having the radio on or talking to myself
I'm almost embarassed to admit that neither of my cars have radios. The Flea never came with one, and the previous owner yanked it out of the blue car. I stick one in my ear on longer trips. Around town I don't miss it though.

Quote:
Originally Posted by Peakster View Post
Doesn't the coasting in gear trickle some energy back into the batteries? Sort of like a radio controlled car.
Not in this car - no regen. Regeneration isn't common in DC conversions. The AC cars have it though.

Andrew: I'd have to say that the video was definitely not a demonstration of hyperwatting. I pretty much had the go pedal mashed to the floor all the time I was accelerating, and I used the brakes in the vid more than I typically do.
__________________
Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
Mitsu mods: 70 MPG in my ecomodded, dirt cheap, 3-cylinder Mirage.
Ecodriving test: Manual vs. automatic transmission MPG showdown



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
Old 03-17-2008, 02:55 AM   #6 (permalink)
Liberti
 
LostCause's Avatar
 
Join Date: Feb 2008
Location: California
Posts: 504

Thunderbird - '96 Ford Thunderbird
90 day: 27.75 mpg (US)
Thanks: 0
Thanked 7 Times in 7 Posts
Since you are the site's driving technique guru, have you ever thought of posting similar videos of driving technique in ICE cars?

I'd love to visually see when EOC is used, coasting distances, cornering speed, acceleration, gear selection choices, timing, defensive driving tactics, and other advanced driving techniques.

It would be a great resource that's unprecedented as far as I know. (If it's not, feel free to direct me to where I may find them...) I suppose the only caveat is that some of those techniques are illegal...

In any case, awesome stuff.

- LostCause
  Reply With Quote
Old 03-17-2008, 11:12 AM   #7 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,527

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

MPGiata - '90 Mazda Miata
90 day: 54.46 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car Mirage - '14 Mitsubishi Mirage ES (base)
90 day: 62.14 mpg (US)
Thanks: 4,078
Thanked 6,976 Times in 3,612 Posts
I hadn't thought of doing ICE driving vids ... until I finished this one for the EV. You're right - particularly with the added graphics, it'd be a good way to demonstrate P&G and EOC.

__________________
Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
Mitsu mods: 70 MPG in my ecomodded, dirt cheap, 3-cylinder Mirage.
Ecodriving test: Manual vs. automatic transmission MPG showdown



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
Reply  Post New Thread




Similar Threads
Thread Thread Starter Forum Replies Last Post
Met an unhappy Aveo owner today MetroMPG General Efficiency Discussion 24 10-10-2010 08:03 AM
EOC (keep in neutral or 5th gear?) Pillzilla Hypermiling / EcoDriver's Ed 18 08-25-2009 09:58 PM
Video: Smart vs. Smart EV on Fifth Gear SVOboy Fossil Fuel Free 5 03-05-2008 01:19 AM



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