89 octane = reduced mpg - Page 3 - Honda Civic Forum



Fuel, Oil, Cleaners & Other Maintenance Extending the life of your Civic requires the proper fuel, oil, and cleaners, along with other regularly scheduled maintenance.

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 11-01-2006   #61
Registered!!
iTrader: (2)
 
yamahaSHO's Avatar
 
Join Date: Nov 2005
Location: Omaha, NE
Posts: 127
Rep Power: 0
yamahaSHO is an unknown quantity at this point
Quote:
Originally Posted by cwo715 View Post
idk if this was listed but the higher the octane the harder it is to burn the fuel.. aka 93 octane takes a lot more compression to burn molecules as compared to 89 or 87. Hence the reason for Diesel which is running at a crisp avg of 18:1 or 23:1 compression. So the point in putting in 89 is just going to waste your money . and you can actually do damage sometimes if you run too high of an octane that is not needed for your engine.

I was thinking about goin with 89 for the winter because the gas is more oxygenated so im gonna lose MPG and small amounts of power that i wont notice.
Close, but not totally accurate. Although compression is a factor, it is heat is what you're worried about. Higher octane resists pre-ignition and detonation better. When you compress something, you create heat. If you can get the fuel/air mixture hot enough, it will ignite. With that said, if you go with a higher octane, say 105, and your car runs great with 87, then you are actually likely to lose power as the higher octane will be harder to ignite and burn slower if the temperature is not high enough. You're not likely to do any damage if you use the 105, but you're power and gas mileage may decrease.

In the winter, you have more available oxygen to burn, however, the temperatures are much cooler so higer octane is not needed.

Basically, octane should be related to heat, not so much compression (as heat is created by compression). Aluminum heads, having a clean burning combustion chamber, and being able to expel exhaust (heat), will allow you to run lower octane. 20 years ago, 10:1 or higher was unheard of on a street car that was made to run on low-grade gasoline.

Diesels run on such high octane (diesel fuel) because the create a lot of heat from the compression. They are also MUCH more effecient than a gasoline engine.
yamahaSHO is offline   Reply With Quote
Old 11-01-2006   #62
I just burnt my tongue
iTrader: (8)
 
ragingSPAM's Avatar
 
Join Date: Mar 2004
Location: Chino Hills, CA
Age: 30
Posts: 4,995
Rep Power: 208
ragingSPAM is just really niceragingSPAM is just really niceragingSPAM is just really niceragingSPAM is just really niceragingSPAM is just really nice
wow those of you who use anything more than 87 in a stock civic are pretty uninformed...

basically the higher the octane on gas is the harder it is to burn
higher octane gas will not improve mileage or power because if your car is not suited for it than it will have a harder time burning all of the fuel that is in the cylinder...
when an engine compresses an air fuel mixture its usually designed to run on a certain fuel so all of the mixture is burned and you get the most out of the cycle...
but once u put higher octane fuels in the system designed for lower octane fuels it has a harder time burning because its compression isnt creating enough heat to burn all of it when the spark plug ignites so a lot of excess fuel is dumped out but is filtered by the catalytic converter thats why you dont smell it but it still is getting dumped out...it makes your car run rich, and uses up more gas so you're actually getting less gas mileage out of your car...

Last edited by ragingSPAM; 11-01-2006 at 06:36 PM.
ragingSPAM is offline   Reply With Quote
Old 11-01-2006   #63
Registered!!
iTrader: (6)
 
ronaldo9's Avatar
 
Join Date: May 2006
Location: North Brunswick, New Jersey
Age: 33
Posts: 1,713
Rep Power: 169
ronaldo9 has a reputation beyond reputeronaldo9 has a reputation beyond reputeronaldo9 has a reputation beyond reputeronaldo9 has a reputation beyond reputeronaldo9 has a reputation beyond reputeronaldo9 has a reputation beyond reputeronaldo9 has a reputation beyond reputeronaldo9 has a reputation beyond reputeronaldo9 has a reputation beyond reputeronaldo9 has a reputation beyond reputeronaldo9 has a reputation beyond repute
Somebody sticky this thread if it already isn't!!!!!
ronaldo9 is offline   Reply With Quote
Old 11-01-2006   #64
Registered!!
 
lxcivic2k1's Avatar
 
Join Date: Jun 2004
Location: St. Louis
Age: 29
Posts: 1,998
Rep Power: 174
lxcivic2k1 is a jewel in the roughlxcivic2k1 is a jewel in the roughlxcivic2k1 is a jewel in the roughlxcivic2k1 is a jewel in the rough
Quote:
Originally Posted by ronaldo9 View Post
Somebody sticky this thread if it already isn't!!!!!
x2 ppl need to know!
lxcivic2k1 is offline   Reply With Quote
Old 11-04-2006   #65
Registered!!
 
Join Date: Oct 2006
Location: honolulu hawaii
Posts: 100
Rep Power: 0
enjoitofer is an unknown quantity at this point
well i put 89 octane when i first got my car but it ran like doo doo then i read the manual then it say should use 92 octane and bla bla bla like that so i been using it ever since and my car works great.
enjoitofer is offline   Reply With Quote
Old 11-04-2006   #66
Registered!!
iTrader: (2)
 
yamahaSHO's Avatar
 
Join Date: Nov 2005
Location: Omaha, NE
Posts: 127
Rep Power: 0
yamahaSHO is an unknown quantity at this point
Quote:
Originally Posted by enjoitofer View Post
well i put 89 octane when i first got my car but it ran like doo doo then i read the manual then it say should use 92 octane and bla bla bla like that so i been using it ever since and my car works great.
Most of that is probably in your head. This motor has great cooling ability considering it is all aluminum. If it was running bad on 89, you probably got bad gas.

I'd give 89 a try again...
yamahaSHO is offline   Reply With Quote
Old 11-04-2006   #67
Premium Member
Hey! Look At Me!! I'm a Supporting Member!!
iTrader: (95)

 
Join Date: Sep 2002
Location: NV
Age: 36
Posts: 51,304
Rep Power: 701
gearbox has a reputation beyond reputegearbox has a reputation beyond reputegearbox has a reputation beyond reputegearbox has a reputation beyond reputegearbox has a reputation beyond reputegearbox has a reputation beyond reputegearbox has a reputation beyond reputegearbox has a reputation beyond reputegearbox has a reputation beyond reputegearbox has a reputation beyond reputegearbox has a reputation beyond repute
Quote:
Originally Posted by enjoitofer View Post
well i put 89 octane when i first got my car but it ran like doo doo then i read the manual then it say should use 92 octane and bla bla bla like that so i been using it ever since and my car works great.
haha the manual says 87 in a civic, it will give the best mileage and performance. maybe you picked up the manual for dads s2k by mistake
gearbox is offline   Reply With Quote
Old 11-05-2006   #68
Falken Master
iTrader: (13)

 
cwo715's Avatar
 
Join Date: Sep 2005
Age: 32
Posts: 1,170
Rep Power: 151
cwo715 is just really nicecwo715 is just really nicecwo715 is just really nicecwo715 is just really nice
yea where in the manual does it say use 92 octane... idk where your at but last time i checked the octane ratings are 87, 89, 91, 93, 97, 102, 108, 119 (which is ethanol based)
cwo715 is offline   Reply With Quote
Old 11-05-2006   #69
Registered!!
iTrader: (2)
 
yamahaSHO's Avatar
 
Join Date: Nov 2005
Location: Omaha, NE
Posts: 127
Rep Power: 0
yamahaSHO is an unknown quantity at this point
Quote:
Originally Posted by cwo715 View Post
yea where in the manual does it say use 92 octane... idk where your at but last time i checked the octane ratings are 87, 89, 91, 93, 97, 102, 108, 119 (which is ethanol based)


The octane ratings you're used to are local. You can get other octane ratings here. Our standard 3 here in CO at most gas stations is 85, 87, 91. On the track I use 105.
yamahaSHO is offline   Reply With Quote
Old 11-05-2006   #70
In love with Diana...te amo
 
boricua_civic's Avatar
 
Join Date: Aug 2005
Location: The Island of Enchantment, Puerto Rico!
Posts: 3,914
Rep Power: 197
boricua_civic has a reputation beyond reputeboricua_civic has a reputation beyond reputeboricua_civic has a reputation beyond reputeboricua_civic has a reputation beyond reputeboricua_civic has a reputation beyond reputeboricua_civic has a reputation beyond reputeboricua_civic has a reputation beyond reputeboricua_civic has a reputation beyond reputeboricua_civic has a reputation beyond reputeboricua_civic has a reputation beyond reputeboricua_civic has a reputation beyond repute
Quote:
Originally Posted by gearbox View Post
haha the manual says 87 in a civic, it will give the best mileage and performance. maybe you picked up the manual for dads s2k by mistake
haha I used to use 93 but the car was too fast for me
boricua_civic is offline   Reply With Quote
Old 11-05-2006   #71
Registered!!
 
Join Date: Oct 2006
Location: honolulu hawaii
Posts: 100
Rep Power: 0
enjoitofer is an unknown quantity at this point
i live in hawaii well i guess the rating is diferant each state cause we have 87,89,92,100 octane
enjoitofer is offline   Reply With Quote
Old 11-05-2006   #72
I just burnt my tongue
iTrader: (8)
 
ragingSPAM's Avatar
 
Join Date: Mar 2004
Location: Chino Hills, CA
Age: 30
Posts: 4,995
Rep Power: 208
ragingSPAM is just really niceragingSPAM is just really niceragingSPAM is just really niceragingSPAM is just really niceragingSPAM is just really nice
we have some 76 stations which have 100 octane gas...but that usually costs on average of $6.50-8.00 per gallon
ragingSPAM is offline   Reply With Quote
Old 11-05-2006   #73
Registered!!
iTrader: (2)
 
yamahaSHO's Avatar
 
Join Date: Nov 2005
Location: Omaha, NE
Posts: 127
Rep Power: 0
yamahaSHO is an unknown quantity at this point
The higher in altitude you go, the more likely you'll have lower octane at the pump.
yamahaSHO is offline   Reply With Quote
Old 11-07-2006   #74
Registered!!
 
SOHC_VTEC_pwr's Avatar
 
Join Date: Oct 2005
Location: Lexington, NC
Age: 29
Posts: 84
Rep Power: 0
SOHC_VTEC_pwr is an unknown quantity at this point
lets take this to mythbusters!!!
SOHC_VTEC_pwr is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Honda Civic Forum Replies Last Post
CV Axle Replacement - '97 Civic DX bashea 6th Generation Civic 1 09-15-2015 05:59 AM
GAS: Best brand (top tier) and type (regular) of gas for mpg & maintenance? SidCivic Mechanical Problems/Vehicle Issues and Fix-it Forum 14 09-12-2015 06:28 PM
2006 EX Manual Coupe - High Milage Cars, Any Issues? John2009 8th & 9th Generation Civic 3 09-10-2015 10:53 PM
New alternator is overcharging already? Bricoleur I.C.E. & Electrical 4 09-09-2015 01:23 PM
2003 Honda Civic Hybrid MPG drop frisbeeguy2 Mechanical Problems/Vehicle Issues and Fix-it Forum 5 07-30-2015 04:00 PM


Tags
2010, 87, 89, 92, 991, civic, compression, fuel, gas, honda, makes, octane, pump, ratio, safe, takes

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 07:10 AM.


All Content Copyright 2007 CivicForums.com