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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 08-21-2011, 09:51 PM   #1 (permalink)
Grrr :-)
 
Nerys's Avatar
 
Join Date: May 2008
Location: Levittown PA
Posts: 800

Cherokee - '88 Jeep Cherokee
90 day: 19.44 mpg (US)

Ryo-Ohki - '94 Geo Metro Xfi
90 day: 50.15 mpg (US)

Vger 2 - '00 Plymouth Grand Voyager SE

Ninja - '89 Geo Tracker
90 day: 30.27 mpg (US)
Thanks: 12
Thanked 31 Times in 25 Posts
Extreme Heat and Humidity = HUGE MPG gains

OK I REALLY hate hot and humid but Ryo-Oki LOVES it. I mean REALLY REALLY loves it.

I had to try hard NOT to get 60mpg and better !!

now that its going away my MPG's are going down.

So how much is there in this? both my pop (96 town car) and my brother (84 carb buick) both remarked that the last few tanks they REALLY saw visible measurable increases in FE so it was not just my "skills" causing this :-) the towncar also has a fuel computer so he can get instant and average measurements.

he saw a 1.5 to 2.5 average mpg increase during this hot and humid spell (for a 22-24mpg car thats huge)

SO is there anything we can do to SIMULATE this?

how much of it was heat how much was humidity??? (mild form of water injection???) I hear water injection increases "power" and more power for us means we need "less foot" to go so better FE.

This might be part of the reason my washed gas gives me so much of an increase ?? some from lack of ethanol and some from left over "water" in solution in the gas ???

anyone have anything concrete on this ??

if I directed my intake over my manifold and sealed up the bottom (partial belly pan) to increase the "heat bank" inside the engine bay to feed the intake.

what would happen? what about heating coils INSIDE the intake? water pump pumping coolant through copper tubes wrapped around the exhaust and coiled inside the intake air tube. ie "that much more heat" to add to the mix.

suggestions? thoughts? ideas? info?

anyone else seeing these results over this past heat humidity wave?

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 08-22-2011, 02:03 AM   #2 (permalink)
Engineering first
 
bwilson4web's Avatar
 
Join Date: Mar 2009
Location: Huntsville, AL
Posts: 792

14 i3-REx - '14 BMW i3-REx
Last 3: 45.67 mpg (US)

17 Prime Plus - '17 Toyota Prius Prime Plus
90 day: 58.25 mpg (US)
Thanks: 79
Thanked 196 Times in 126 Posts
Quote:
Originally Posted by Nerys View Post
OK I REALLY hate hot and humid but Ryo-Oki LOVES it. I mean REALLY REALLY loves it.
. . .
SO is there anything we can do to SIMULATE this?
. . .
I've observed two effects with my Prius:
  • lower air density - several years ago in a winter drive to South Carolian and back, the temperatures ranged from 15F -> 40F -> 18F and the highway fuel economy followed the change in air density as a function of temperature.
  • warm-up effects - engine, transmission and tire warm-up takes about 5 minutes until things plateau. Warmer weather reduces the warm-up by starting a few degrees higher and with lower heat loss during the warm-up interval. Tire pressures are also likely to be higher from heating.
__________________
2019 Std. Range Plus Model 3 - 134 MPG3 || 2014 BMW i3-REx - 117 MPGe, 39 MPG
JuiceBox 40 Pro (240 VAC, 40 A), KHONS portable (120-240 VAC, 12-32 A)
Retired engineer, Huntsville, AL (five times AutoPilot saved.)
  Reply With Quote
Old 08-22-2011, 02:16 AM   #3 (permalink)
Polymorphic Modder
 
SoobieOut's Avatar
 
Join Date: Aug 2010
Location: Utah
Posts: 307

2006 DaCivic Hybrid - '06 Honda Civic Hybrid
90 day: 45.16 mpg (US)
Thanks: 188
Thanked 39 Times in 24 Posts
I agree with bwilson here. High Humidity and Temperature will lower the apparent drag from the air.

In aviation terms they call this a high density altitude, requiring longer runways for take-off on hot humid days.
  Reply With Quote
Old 08-22-2011, 02:54 AM   #4 (permalink)
MPGuino Supporter
 
t vago's Avatar
 
Join Date: Oct 2010
Location: Cedar Rapids, IA
Posts: 1,766

The Karen-Mobile - '05 Dodge Magnum SXT
Team Dodge
90 day: 26.72 mpg (US)

Fiat Dakota - '00 Dodge Dakota SLT RWD Quad Cab
90 day: 16.67 mpg (US)

The Red Sled - '01 Dodge Durango SLT 4WD
90 day: 16.96 mpg (US)
Thanks: 799
Thanked 682 Times in 437 Posts
You also have to consider that, on humid and warm days, there is effectively less oxygen being drawn into the engine, compared to cooler and less humid days. This requires that the driver open up the throttle a bit more to get the same amount of output power, which will reduce pumping losses in the engine. This will also cause fuel efficiency to go up.
__________________
The Fiat Dakota


The Karen-mobile


The Red Sled
  Reply With Quote
Old 08-22-2011, 10:05 AM   #5 (permalink)
EV convert
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 9,709

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: 141.63 mpg (US)
Thanks: 231
Thanked 3,169 Times in 2,486 Posts
Quote:
Originally Posted by Nerys View Post
SO is there anything we can do to SIMULATE this?

suggestions? thoughts? ideas? info?
Maybe a warm air intake with mild water injection.
Only problem with water injection is its not proven to boost FE on N/A gas engines at least with stock cold air type intakes.

For FE on a gas engine during compression you want your air/fuel mix to get as hot as possible with out preignition and with out having to pull timing before being lit off by the spark plug.
  Reply With Quote
Old 08-22-2011, 11:31 AM   #6 (permalink)
Grrr :-)
 
Nerys's Avatar
 
Join Date: May 2008
Location: Levittown PA
Posts: 800

Cherokee - '88 Jeep Cherokee
90 day: 19.44 mpg (US)

Ryo-Ohki - '94 Geo Metro Xfi
90 day: 50.15 mpg (US)

Vger 2 - '00 Plymouth Grand Voyager SE

Ninja - '89 Geo Tracker
90 day: 30.27 mpg (US)
Thanks: 12
Thanked 31 Times in 25 Posts
well thats what I am curious about. was it just the heat? or the combo of heat and humidity? you see it was 100+ degree's for several days with humidity over 95%

ie TRULY nasty. we do not "get" 100' days with "low" humidity so I can't test.

I am curious to see what people in other climes get. ie do people in not quite so hot but almost always NASTY HUMID florida see the same higher mpg?

what about people in nevada and arizona? ie super hot but LOW humidity?

is it one or the other? or do you require BOTH to see these results? is it possible for us to simulate this even partially?
  Reply With Quote
Old 08-22-2011, 03:00 PM   #7 (permalink)
EV convert
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 9,709

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: 141.63 mpg (US)
Thanks: 231
Thanked 3,169 Times in 2,486 Posts
The humidity could aid in preventing preignition.
  Reply With Quote
Old 08-22-2011, 03:01 PM   #8 (permalink)
Grrr :-)
 
Nerys's Avatar
 
Join Date: May 2008
Location: Levittown PA
Posts: 800

Cherokee - '88 Jeep Cherokee
90 day: 19.44 mpg (US)

Ryo-Ohki - '94 Geo Metro Xfi
90 day: 50.15 mpg (US)

Vger 2 - '00 Plymouth Grand Voyager SE

Ninja - '89 Geo Tracker
90 day: 30.27 mpg (US)
Thanks: 12
Thanked 31 Times in 25 Posts
Hmmm what would cause pre ignition?
  Reply With Quote
Old 08-22-2011, 03:19 PM   #9 (permalink)
Efficiency Aficionado
 
CigaR007's Avatar
 
Join Date: Jul 2010
Location: Canada
Posts: 645

GreenTurtle (Retired) - '01 Toyota Echo Sedan
90 day: 44.85 mpg (US)

Zulu - '14 Honda CR-Z
90 day: 47.95 mpg (US)
Thanks: 141
Thanked 178 Times in 119 Posts
Quote:
Originally Posted by Nerys View Post
Hmmm what would cause pre ignition?

If the temperature of the air/fuel mixture entering the cylinder is already quite high, it will be further increased during the compression cycle, meaning there is a risk of pre-ignition; or the mixture igniting itself (compression = heat) without the need of the spark plug; which is bad.

Somebody correct me if I am wrong.
  Reply With Quote
Old 08-22-2011, 03:20 PM   #10 (permalink)
Grrr :-)
 
Nerys's Avatar
 
Join Date: May 2008
Location: Levittown PA
Posts: 800

Cherokee - '88 Jeep Cherokee
90 day: 19.44 mpg (US)

Ryo-Ohki - '94 Geo Metro Xfi
90 day: 50.15 mpg (US)

Vger 2 - '00 Plymouth Grand Voyager SE

Ninja - '89 Geo Tracker
90 day: 30.27 mpg (US)
Thanks: 12
Thanked 31 Times in 25 Posts
ahh so the humidity (ie water in the air) would dampen this. I get it. so it might be critical to have BOTH present.

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com