Toyota Yaris Forums - Ultimate Yaris Enthusiast Site
 

 


 
Go Back   Toyota Yaris Forums - Ultimate Yaris Enthusiast Site > Technical Forums > DIY / Maintenance / Service
  The Tire Rack

Reply
 
Thread Tools Display Modes
Old 12-30-2006, 02:23 AM   #1
KSIbucky
 
KSIbucky's Avatar
 
Drives: 2007 Yaris manual dark silver
Join Date: May 2006
Location: Fond du Lac, WI
Posts: 694
Send a message via AIM to KSIbucky Send a message via MSN to KSIbucky
higher octane fuel

Can a higher octane hurt a car (spark plugs) just wondering. I know some people that think they can ho faster and do all this stuff cool amazing stuff (fly, go back in tiime, end world hunger, and fight polio) with that magic 93 octane.
__________________
7 Color Tach
Fujita Intake
Momo pedals Shift knob and boot. Full TRD SSK.
Blitz exhaust
Megan Lowering Springs
(Next is DC Header)
KSIbucky is offline   Reply With Quote
Old 12-30-2006, 02:46 AM   #2
spkrman
Banned
 
Drives: 1
Join Date: Nov 2006
Location: 2
Posts: 1,476
seems to boost my top end and give better mileage when driven hard... same 300 mile trip with 87 and 92 got 32 and 35mpg respectively, both were mostly 80 with some sprints to 100... although I was a little more conservative with the 87 it still got worse mileage.
spkrman is offline   Reply With Quote
Old 12-30-2006, 10:40 AM   #3
acrbill
 
Drives: Polar White Hatch
Join Date: Nov 2006
Location: chicago
Posts: 407
If it was any other car I would say that it would hurt mileage and power. For those who don't know, the higher the octane the slower the fuel burns, so basically you want the lowest octane you can get away with for max power.

This car has 10.5:1 compression though. The ecu must set the timing really low to get the car to run on regular gas. You have to wonder how much power is being hidden by the 87 octane tune. You also have to ask yourself if the ecu could adapt to 93 octane and give you more power.

In my old Neon it recommended premium fuel. You could put regular fuel in but mileage and performance would suffer.
__________________
http://home.comcast.net/~job0b/ywsig.gif
ChinoCharles Intake supporter.
acrbill is offline   Reply With Quote
Old 12-30-2006, 04:16 PM   #4
captainzerocool
CAMRY FTW!
 
captainzerocool's Avatar
 
Drives: Camry LE V-6 (225,000+ miles)
Join Date: Jul 2006
Location: Huntsville, Ala
Posts: 108
I have seen a noticeable improvement in mileage jumping to 89 from the 87 octane.
__________________
I drive a Camry.

I have no imagination.
captainzerocool is offline   Reply With Quote
Old 12-30-2006, 04:21 PM   #5
acrbill
 
Drives: Polar White Hatch
Join Date: Nov 2006
Location: chicago
Posts: 407
Quote:
Originally Posted by captainzerocool View Post
I have seen a noticeable improvement in mileage jumping to 89 from the 87 octane.
I am going to give 89 a try for the next fill up.
__________________
http://home.comcast.net/~job0b/ywsig.gif
ChinoCharles Intake supporter.
acrbill is offline   Reply With Quote
Old 12-30-2006, 08:25 PM   #6
Black Yaris
der Zeck
 
Black Yaris's Avatar
 
Drives: '05 Audi A4 1.8t quattro
Join Date: Sep 2006
Location: Toledo, OH
Posts: 5,231
I think I am going for an octane upgrade next fill up as well, has anyone tried an octane booster aditive?
__________________
Black Yaris is offline   Reply With Quote
Old 12-30-2006, 08:30 PM   #7
acrbill
 
Drives: Polar White Hatch
Join Date: Nov 2006
Location: chicago
Posts: 407
Quote:
Originally Posted by Black Yaris View Post
I think I am going for an octane upgrade next fill up as well, has anyone tried an octane booster aditive?
Don't bother with that junk. Just mix in some higher octane with the regular if you feel the need.
__________________
http://home.comcast.net/~job0b/ywsig.gif
ChinoCharles Intake supporter.
acrbill is offline   Reply With Quote
Old 12-30-2006, 08:32 PM   #8
Black Yaris
der Zeck
 
Black Yaris's Avatar
 
Drives: '05 Audi A4 1.8t quattro
Join Date: Sep 2006
Location: Toledo, OH
Posts: 5,231
I never realy tried an octane booster, just wondering if anyone has...
__________________
Black Yaris is offline   Reply With Quote
Old 12-30-2006, 08:41 PM   #9
acrbill
 
Drives: Polar White Hatch
Join Date: Nov 2006
Location: chicago
Posts: 407
putting additives in your tank can sometime mess up the sending unit. I put a few cap fulls of Marvels Mystery oil into my Neons tank and it read 3/4 after a fill up.
__________________
http://home.comcast.net/~job0b/ywsig.gif
ChinoCharles Intake supporter.
acrbill is offline   Reply With Quote
Old 01-03-2007, 12:19 AM   #10
PetersRedYaris
 
PetersRedYaris's Avatar
 
Drives: 2005 Scion xB
Join Date: Nov 2006
Location: The Black Hills of South Dakota
Posts: 1,059
I'm not big on fuel additives. I did however get better mileage with 91 (premium here in SD) octane fuel but didn't record the exact numbers.
PetersRedYaris is offline   Reply With Quote
Old 01-03-2007, 09:44 AM   #11
nsmitchell
 
nsmitchell's Avatar
 
Drives: LB-Auto-PWR-ABS-Cruise-Springs
Join Date: Aug 2006
Location: Richmond, VA
Posts: 1,065
For what it's worth, I paid the extra 20 cents per gallon ($2.00) for super unleaded (91 octane) yesterday. Since our engines have a fairly high compression ratio I figured I'd give it a go and see. Should I disconnect my battery to reset the ECU?
__________________
Other car is a 2005 Mustang Convertible 4.0L V6 Manual - Legend Lime
Get YarAss in gear!
RIP - Casey Tatum
nsmitchell is offline   Reply With Quote
Old 01-03-2007, 11:44 AM   #12
daq421
MPG is the new cool
 
daq421's Avatar
 
Drives: 07 Yaris sedan (silver) Auto
Join Date: Sep 2006
Location: Livermore, CA
Posts: 116
Send a message via AIM to daq421
Someone put some hard numbers in this thread please. I'd love to know if the MPG increase (whatever it may be) actually offset extra 20 to 35 cents per gallon it would cost to run Super over regular unleaded..

-Peter
__________________
daq421 is offline   Reply With Quote
Old 01-03-2007, 06:48 PM   #13
07WYarisRS
HardlyDangerous
 
07WYarisRS's Avatar
 
Drives: 09 Yaris LE, H/B, auto
Join Date: Jul 2006
Location: Ridgeway Ontario
Posts: 573
Higher octane fuel don't burn slower...in most cases burn rates are the same provding the fuel additives are the same in both octane fuels.... if they do it's because of additives in the fuel, ill get to that later. A higher octane simply means it has a higher flash point meaning it takes more heat and compression to ignite the mixture.
10.5:1 is not a high compression engine and does not require a high octane fuel. Sure it's a bit higher then many cars but many bikes have compression of 12:1 and still run 87 octane. A lot depends on the combustion chamber design, timing and fuel maps.

Octane boosters don’t really bump up the octane of the fuel
Most only 3-7 points witch is less then one octane level. Octane booster do however contain additives the remove or neutralize free radicals in the fuel that promote detonation and pre-ignition.

Because higher octane fuels have a higher flash point; meaning is it takes more heat to ignite. Higher compression creates more heat. So to avoid igniting the a/f charge prematurely you want something that has a higher flash point. If your engine don't have any problems with the engine suffering from detonation or pre-ignition you don't have to worry about using a higher octane fuel. it won't do anything.

Additives or lack of, in the fuel can help to increase or decrease the burn rate slightly as well. Running a higher octane fuel in of itself will not increase HP. This is a myth.
Rule of thumb is only run the amount of octane needed to prevent detonation or pre-ignition of the fuel. Run anything over that and there will be a loss in power as the fuel/air mixture is not able to burn completely.
Black smoke or carbon collecting in the exhaust tip is a sign of a rich mixture and/or the engine not being able to burn all of the fuel completely. Runnning a higher octane then the engine needs or was designed to run can and often will shorten the life of the polution control system (cat convertor and oxygen sensors)

Think about it...why design a econo box if it requires or performs better on the most costly fuels available....
Stick with the 87 or if you are hauling a heavy load or lots of passengers bump up to an 89
__________________
The early bird gets the worm, but the second mouse gets the cheese.
07WYarisRS is offline   Reply With Quote
Old 01-03-2007, 09:15 PM   #14
eTiMaGo
vroom vroom
 
eTiMaGo's Avatar
 
Drives: lil red 5-door
Join Date: Sep 2006
Location: Bangkok, Thailand
Posts: 7,744
Send a message via AIM to eTiMaGo Send a message via MSN to eTiMaGo Send a message via Yahoo to eTiMaGo
Interesting read... I wonder if the engines here are tuned differently, as 91 octane is the lowest you can get, as well as 95...
__________________
The price of freedom of religion, or of speech, or of the press, is that we must put up with a good deal of rubbish.
- Robert Jackson


Bye bye 1NZ...
eTiMaGo is offline   Reply With Quote
Old 01-03-2007, 10:21 PM   #15
spkrman
Banned
 
Drives: 1
Join Date: Nov 2006
Location: 2
Posts: 1,476
duno, better top end and better mileage for me... I don't think the 2-3mpg increase I've seen offsets additional cost.

The manual doesn't say you can't run 93, it says run at least 87.

As far as any dyno's I've seen, higher octane fuels increase power?
spkrman is offline   Reply With Quote
Old 01-03-2007, 11:20 PM   #16
johnnyfive
 
johnnyfive's Avatar
 
Drives: 2007 Yaris S
Join Date: May 2006
Location: Milwaukee WI
Posts: 582
Quote:
Originally Posted by eTiMaGo View Post
Interesting read... I wonder if the engines here are tuned differently, as 91 octane is the lowest you can get, as well as 95...
i belive it is just a differance in how the octane is rated, i cant remeber any details on it..but i do belive that your lower octane is an equivilent to the north american lower octanes...
johnnyfive is offline   Reply With Quote
Old 01-05-2007, 10:36 AM   #17
jaspie
Lil White her name is ~
 
jaspie's Avatar
 
Drives: White YRX 5DR Hatchback 2006
Join Date: Dec 2006
Location: Gold Coast/Brisbane, Queensland, Australia
Posts: 268
I find it strange ~ That you guys are talking about 87.....89.....91.....93 octane fuel ~

Here in Australia we have 95.....98 and 100 octane fuel ~ I fill up with 98 octane fuel and there is quite a big difference with the regular fuel ~

That's my opinion anyway ~

Jaspie ~
jaspie is offline   Reply With Quote
Old 01-05-2007, 03:48 PM   #18
Yarii
 
Drives: n/a
Join Date: Aug 2006
Location: Canada
Posts: 24
North America measures octane differently than the rest of the world so it's numbers do look lower. That said, I'm pretty sure american 87octane is slightly lower than the average regular in Europe. Probably why (or because) european cars have high compression rates, and american cars run a pathetic inefficient 8.5 or 9:1.
Yarii is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Fuel Economy swng Fuel Economy Forum 2089 01-23-2015 06:41 PM
Increased MPG or HP anyone???? slvryaris Performance Modifications 55 05-27-2007 10:49 AM
I'd like to know this right now.. is brand name gas better for my new Yaris? fantabulousbaby General Yaris / Vitz Discussion 12 09-19-2006 09:14 PM
Consumer Reports on Ethanol Driver General Yaris / Vitz Discussion 6 09-01-2006 11:21 AM
What octane fuel is recommended? sroberts General Yaris / Vitz Discussion 4 06-09-2006 08:54 PM


All times are GMT -4. The time now is 04:12 AM.




YarisWorld
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.