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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 06-18-2008, 12:52 PM   #11 (permalink)
Master EcoModder
 
NeilBlanchard's Avatar
 
Join Date: May 2008
Location: Maynard, MA Eaarth
Posts: 7,907

Mica Blue - '05 Scion xA RS 2.0
Team Toyota
90 day: 42.48 mpg (US)

Forest - '15 Nissan Leaf S
Team Nissan
90 day: 156.46 mpg (US)

Number 7 - '15 VW e-Golf SEL
TEAM VW AUDI Group
90 day: 155.81 mpg (US)
Thanks: 3,475
Thanked 2,950 Times in 1,844 Posts
Hello,

As I understand it, there is actually less potential energy in higher octane fuel. So, if you don't need it to prevent knocking, then save your money.

__________________
Sincerely, Neil

http://neilblanchard.blogspot.com/
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 06-18-2008, 06:08 PM   #12 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,513

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

MPGiata - '90 Mazda Miata
90 day: 52.71 mpg (US)

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

Appliance car - '14 Mitsubishi Mirage ES (base)
90 day: 60.16 mpg (US)
Thanks: 4,058
Thanked 6,957 Times in 3,602 Posts
Quote:
Originally Posted by RH77 View Post
Which parameters to choose?
Even if you could compute FE from the params, would you be confident you could distinguish a few percent difference, if any, by switching fuels?

Unless you burn a LOT of fuel driving the exact same route day in & day out, you're facing the same data reliability issues everyone has who wants to test fuel and/or additives.

That said, by default, I think I'd probably go with regular in a car with a knock sensor.
__________________
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 06-19-2008, 12:14 AM   #13 (permalink)
Depends on the Day
 
RH77's Avatar
 
Join Date: Nov 2007
Location: Kansas City Area
Posts: 1,761

Teggy - '98 Acura Integra LS
Sports Cars
90 day: 32.74 mpg (US)

IMA - '10 Honda Insight EX
Team Honda
90 day: 34.76 mpg (US)

Tessie - '06 Acura TSX Base
90 day: 28.2 mpg (US)
Thanks: 31
Thanked 41 Times in 35 Posts
Quote:
Originally Posted by MetroMPG View Post
Even if you could compute FE from the params, would you be confident you could distinguish a few percent difference, if any, by switching fuels?

Unless you burn a LOT of fuel driving the exact same route day in & day out, you're facing the same data reliability issues everyone has who wants to test fuel and/or additives.

That said, by default, I think I'd probably go with regular in a car with a knock sensor.
Good points.

The vehicle is a commuter for my Wife (to work and school both), who has the same route except for the weekends. I would say she fills once a week -- FE is pretty stable at 29-31 this time of year (unless I drive it ). If it dips down to 27 or 28, then it may not be worth it (which is what happened during Winter). But Winter is Winter, as we know.

So, should the ECU be reset for such a change, or would that make it an unfair learning curve for a baseline?

We'll fill up with Reg next time 'round and see how it goes.

RH77
__________________
“If we knew what we were doing, it wouldn't be called research” ― Albert Einstein

_
_
  Reply With Quote
Old 06-19-2008, 12:22 AM   #14 (permalink)
EcoModding Apprentice
 
Join Date: Jan 2008
Location: kansas city, MO
Posts: 103

Hyundai Accent - '01 Hyundai Accent
90 day: 38.4 mpg (US)

Gixer - '97 Suzuki GSXR600
90 day: 43.12 mpg (US)
Thanks: 2
Thanked 0 Times in 0 Posts
Just to further complicate things, the octane rating on the pump is the minimum octane for that grade. there is no rule about them selling a higher octane than stated. In states where ethanol must be blended in 5 or 10 percent with regular gasoline, the "regular" might be the same octane as the mid grade or premium.
__________________
  Reply With Quote
Old 06-19-2008, 11:14 AM   #15 (permalink)
EcoModding Lurker
 
Join Date: Jun 2008
Location: Rhode Island
Posts: 17

Mr. Miragi - '96 Mitsubishi Mirage S
90 day: 27.45 mpg (US)
Thanks: 0
Thanked 1 Time in 1 Post
higher octane gas also lets you run at a lower rpm without lugging it. On 87 my mirage wont do 35 mph in fifth. But with 89 or 91 it will do 30 no problem, of course till i get to a hill, but it will still creep up most hills at 35.
  Reply With Quote
Old 06-19-2008, 11:26 AM   #16 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,513

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

MPGiata - '90 Mazda Miata
90 day: 52.71 mpg (US)

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

Appliance car - '14 Mitsubishi Mirage ES (base)
90 day: 60.16 mpg (US)
Thanks: 4,058
Thanked 6,957 Times in 3,602 Posts
Rick: I don't think there's any need to reset the ECU - a knock sensor is an immediate reaction type of thing.

gteclass: good point if you have a manual transmission.
__________________
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 06-19-2008, 02:36 PM   #17 (permalink)
Banned
 
Join Date: Feb 2008
Location: california
Posts: 1,329
Thanks: 24
Thanked 161 Times in 107 Posts
Quote:
Originally Posted by jesse.rizzo View Post
Just to further complicate things, the octane rating on the pump is the minimum octane for that grade. there is no rule about them selling a higher octane than stated. In states where ethanol must be blended in 5 or 10 percent with regular gasoline, the "regular" might be the same octane as the mid grade or premium.
Bingo!

Local tv station did a report on this about a year ago. They took samples of 87 89 and 91 octane from a number of local gas stations to a lab to be analized. They found all the samples tested between 90-92 octane with anywhere between 10-15% ethanol content. All the gasoline came from the same refinery and the only variation was the ammount of ethanol mixed in.
  Reply With Quote
Old 06-19-2008, 05:19 PM   #18 (permalink)
Depends on the Day
 
RH77's Avatar
 
Join Date: Nov 2007
Location: Kansas City Area
Posts: 1,761

Teggy - '98 Acura Integra LS
Sports Cars
90 day: 32.74 mpg (US)

IMA - '10 Honda Insight EX
Team Honda
90 day: 34.76 mpg (US)

Tessie - '06 Acura TSX Base
90 day: 28.2 mpg (US)
Thanks: 31
Thanked 41 Times in 35 Posts
Quote:
Originally Posted by MetroMPG View Post
Rick: I don't think there's any need to reset the ECU - a knock sensor is an immediate reaction type of thing.

gteclass: good point if you have a manual transmission.
Thanks Darin -- now I won't have to lookup the radio code . Also, I can force somewhat of a bog with the manu-matic shift, in 5th, TC lockup, and at the bottom of the speed band (I think it's 50 mph -- I don't drive it all that often, so not sure). I'll be curious as to how it "acts".

Quote:
Originally Posted by tjts1 View Post
All the gasoline came from the same refinery and the only variation was the ammount of ethanol mixed in.
So do they use Xylene anymore? I used to "make" my own racing fuel just by adding xylene to a tank. I was told (at the time -- 2003) that each brand dumps their own additives into the tanker truck just before it leaves for the stations.

What I find interesting is buying gas in the State of Iowa. Mid-Grade is the cheapest (often by 10-20 cents) because it's 10% ethanol (and likely subsidized). 87-octane is the next most expensive, followed by 91.

The first time I saw it, I thought they were having a "Sale" on mid-grade. I don't know if folks remember, many Amoco stations used to have all grades the same price on like Tuesdays or something.

Truthfully, I haven't been bold enough to try it to see if FE plummets (plus, I've been turned off by the current ripple running through the world as a result of ethanol production (and locally with . I do a lot of driving in Iowa

Maybe I'll give it a shot on the mid-grade to see what happens. I often hear of a certain percentage of Ethanol being a good thing for FE.

RH77

__________________
“If we knew what we were doing, it wouldn't be called research” ― Albert Einstein

_
_
  Reply With Quote
Reply  Post New Thread


Tags
octane, premium gas

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mercedes modded C-class: Cd 0.25. Up 7.5 mpg over regular model (with other mods). MetroMPG Aerodynamics 25 04-08-2013 04:57 PM
Different Types of Oil MasterAlex EcoModding Central 12 06-25-2008 10:34 PM
GAS is 4.50 for Regular in Los Angeles dsq EcoModding Central 10 06-06-2008 03:11 PM



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