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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 05-03-2013, 02:25 PM   #1 (permalink)
EcoModding Lurker
 
brekko's Avatar
 
Join Date: Nov 2008
Location: Ohio
Posts: 11

Romulus - '10 Honda Insight EX
90 day: 55.81 mpg (US)
Thanks: 0
Thanked 3 Times in 2 Posts
Insight gauges

I purchased a 2010 Insight a few months ago. After driving with my scanguage for several tanks I've noticed that the built in gauges for the Insight are not correct. The distance till empty always underestimates, and the fuel economy per tank always overestimates. I double checked this with by checking my per tank fuel economy the adhoc way of taking distance traveled divided by gallons filled up. Has anyone else noticed this anomaly?

__________________
dude, you're going 50 on I-75.
  Reply With Quote
The Following User Says Thank You to brekko For This Useful Post:
Cobb (05-05-2013)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 05-03-2013, 03:22 PM   #2 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,532

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: 4,082
Thanked 6,978 Times in 3,613 Posts
That's to be expected. It's more the rule than the exception that factory gauges are inaccurate.

Anecdotally, they usually underestimate fuel consumption. How far off is your factory gauge from reality?
__________________
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 05-03-2013, 03:25 PM   #3 (permalink)
EcoModding Lurker
 
brekko's Avatar
 
Join Date: Nov 2008
Location: Ohio
Posts: 11

Romulus - '10 Honda Insight EX
90 day: 55.81 mpg (US)
Thanks: 0
Thanked 3 Times in 2 Posts
Each tank the overall MPG will be overestimated by about 4-5% while the fuel consumption will be underestimated by about 10%. Unless this is just a safety feature to prevent against people running out of gas. It will read 0 Miles range left, while I will have between 1.5-1.8 gallons left.
__________________
dude, you're going 50 on I-75.
  Reply With Quote
Old 05-04-2013, 02:39 AM   #4 (permalink)
Master EcoModder
 
Join Date: Jun 2008
Location: Earth
Posts: 5,209
Thanks: 225
Thanked 811 Times in 594 Posts
Don't know about the current Insight, but on the Gen 1 Insight the ScanGauge is wildly inaccurate on anything to do with fuel, while the car's gauge is as close as I could readily measure - within a couple of percent or so.
  Reply With Quote
Old 05-04-2013, 12:03 PM   #5 (permalink)
Master EcoWalker
 
RedDevil's Avatar
 
Join Date: Dec 2012
Location: Nieuwegein, the Netherlands
Posts: 3,999

Red Devil - '11 Honda Insight Elegance
Team Honda
90 day: 53.95 mpg (US)
Thanks: 1,714
Thanked 2,247 Times in 1,455 Posts
The range left is underestimated (when near empty) for safety reasons, I guess.
You wouldn't want to fall short of fuel while it indicates there should be some left.

The fuel consumption indicated by the MID is less than the actual consumption calculated from the pump, but in part that can be explained by the fact that the Insight sucks excess vapor from the tank into the air intake. It cannot measure the amount of fuel that evaporates and gets sucked in, it only measures the liquid fuel it uses.

For every tank of fuel a tiny amount will evaporate, so there will be a difference even if all gauges work correctly. The Insight still burns the evaporated fuel, so the pump shows the real consumption.

My MID is 3 to 5 % optimistic on FE.
__________________
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 0.2 Gmeter or 0.13 Mmile.


For confirmation go to people just like you.
For education go to people unlike yourself.
  Reply With Quote
Old 05-04-2013, 02:38 PM   #6 (permalink)
Master EcoModder
 
Join Date: Jun 2008
Location: Earth
Posts: 5,209
Thanks: 225
Thanked 811 Times in 594 Posts
Quote:
Originally Posted by RedDevil View Post
The range left is underestimated (when near empty) for safety reasons, I guess.
And also, I would think, because the estimating is a fundamentally different problem. You could assume that your mpg would be the same as it has been for the last XX miles, but suppose you hit a headwind, have to climb a mountain, or who knows what?

Quote:
The fuel consumption indicated by the MID is less than the actual consumption calculated from the pump, but in part that can be explained by the fact that the Insight sucks excess vapor from the tank into the air intake. It cannot measure the amount of fuel that evaporates and gets sucked in, it only measures the liquid fuel it uses.
But it should be able to compute that, and I think would do so as part of the emissions control system. It knows airflow and fuel injected, and has an oxygen sensor(s) in the exhaust. So X fuel + Y air should give Z O2. If it's more or less due to gasoline vapor, that's detected and X decreased in order to optimize emissions, no?
  Reply With Quote
Old 05-04-2013, 03:25 PM   #7 (permalink)
Master EcoModder
 
Join Date: Sep 2009
Posts: 5,927
Thanks: 877
Thanked 2,024 Times in 1,304 Posts
With modern in tank fuel pumps that are cooled by the fuel in the tank, when you run it completely out of fuel and even when you run it very low, both situations will accelerate the wear on the fuel pump.

I generally refill at just below 1/4 tank for that reason.

regards
Mech
  Reply With Quote
The Following User Says Thank You to user removed For This Useful Post:
Cobb (05-05-2013)
Old 05-04-2013, 03:40 PM   #8 (permalink)
Master EcoWalker
 
RedDevil's Avatar
 
Join Date: Dec 2012
Location: Nieuwegein, the Netherlands
Posts: 3,999

Red Devil - '11 Honda Insight Elegance
Team Honda
90 day: 53.95 mpg (US)
Thanks: 1,714
Thanked 2,247 Times in 1,455 Posts
Quote:
Originally Posted by jamesqf View Post
(about the Insight using but not counting gasoline vapor) But it should be able to compute that, and I think would do so as part of the emissions control system. It knows airflow and fuel injected, and has an oxygen sensor(s) in the exhaust. So X fuel + Y air should give Z O2. If it's more or less due to gasoline vapor, that's detected and X decreased in order to optimize emissions, no?
Maybe it could, but it would not know whether the enriched air is because of the recovery system or because of the overrich mixture of the car in front...
As it happens some G2 Insight owners have reported low FC readings just after filling and topping fuel. The most likely scenario is that their spills ended up enriching the recovery system, reducing the need for adding fuel in the usual way. Every now and then, after I fill up, it seems like the Insight runs almost by itself. The effect lasts just a mile or so.

__________________
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 0.2 Gmeter or 0.13 Mmile.


For confirmation go to people just like you.
For education go to people unlike yourself.
  Reply With Quote
Reply  Post New Thread






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