:octane question??:
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:octane question??:
<noob question of the week>
i have a b20 and i was running 87 octane a while ago. i switched to 89 octane figuring it would be better for my engine and all. it seemed my gas milage suffered a bit. i put 87 octane back into today not realizing and it seem the car has better pick up and runs better...
what should i be running?? thanxx
i have a b20 and i was running 87 octane a while ago. i switched to 89 octane figuring it would be better for my engine and all. it seemed my gas milage suffered a bit. i put 87 octane back into today not realizing and it seem the car has better pick up and runs better...
what should i be running?? thanxx
All Motor Mentor
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From: 902, Nova Scotia, Canada
Re: :octane question??: (jethawk)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jethawk »</TD></TR><TR><TD CLASS="quote">if your car dosent require the higher octane then its just a waste of money...</TD></TR></TABLE>
yep exactly....
yep exactly....
Honda-Tech Member
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From: Hell, Az, USA
Re: :octane question??: (Luserkid)
If you think about it logically, 91 would be the best to run since it burn the cleanest. Basically it like running 110 in a B series.....maybe not the best example but....
Better Fuel = Better Performance
At least thats what I was taught
Better Fuel = Better Performance
At least thats what I was taught
Joined: Sep 2004
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From: JERSEY, USA
Re: :octane question??: (beandip)
i always thought that the octane is the compression rating on the gas before it will combust before the spark hits it. then you get knock, if you arne't getting knock then i wouldn't waste the extra $.20, but for the b series i would stick with high 80s low 90s
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Re: :octane question??: (civiccpedx)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beandip »</TD></TR><TR><TD CLASS="quote">If you think about it logically, 91 would be the best to run since it burn the cleanest. Basically it like running 110 in a B series.....maybe not the best example but....
Better Fuel = Better Performance
At least thats what I was taught</TD></TR></TABLE>
um, NO. you will not get better performance by throwing a high octance in your engine that requires somethingl like 87. if you put high octane in, youll end up with huge carbon deposits, which will actually ROB you of power in the long run. my main point is that put whatever the manufacturer recommends and be done with it.
if youre butt dyno read higher hp will less octance then that was probably placebo. maybe you were reclining more?
Better Fuel = Better Performance
At least thats what I was taught</TD></TR></TABLE>
um, NO. you will not get better performance by throwing a high octance in your engine that requires somethingl like 87. if you put high octane in, youll end up with huge carbon deposits, which will actually ROB you of power in the long run. my main point is that put whatever the manufacturer recommends and be done with it.
if youre butt dyno read higher hp will less octance then that was probably placebo. maybe you were reclining more?
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From: MEMORYFAB.COM
Re: :octane question??: (ek9hatch0WN3R)
my sparco race seat doesnt recline. im not sure what the manufactors suggestion on octane is on a B20. i guess ill just stick with 87 octane for now until the engine build up 
im not sure what the manufactors suggestion on octane is on a B20. i guess ill just stick with 87 octane for now until the engine build up
Honda-Tech Member
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From: Severn, MD
Re: :octane question??: (beandip)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beandip »</TD></TR><TR><TD CLASS="quote">If you think about it logically, 91 would be the best to run since it burn the cleanest. Basically it like running 110 in a B series.....maybe not the best example but....
Better Fuel = Better Performance
At least thats what I was taught</TD></TR></TABLE>
Totally incorrect. Octane has got nothing to do with how 'clean' it burns. Higher octane gas actually burns slower than lower octane gas.
Better Fuel = Better Performance
At least thats what I was taught</TD></TR></TABLE>
Totally incorrect. Octane has got nothing to do with how 'clean' it burns. Higher octane gas actually burns slower than lower octane gas.
All Motor Mentor
Joined: Aug 2004
Posts: 6,987
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From: 902, Nova Scotia, Canada
Re: :octane question??: (EE_Chris)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris »</TD></TR><TR><TD CLASS="quote">
Totally incorrect. Octane has got nothing to do with how 'clean' it burns. Higher octane gas actually burns slower than lower octane gas.</TD></TR></TABLE>
Exactly right. All Octane does is raise the ignition point of the fuel which allows a car that is running higher compression or a more agressive ignition curve to make more power. I'm sure you've all heard an older car "pinging" while going up hill or cruising on the highway while under load. That's called pre-ignition or detonation and it comes from excess carbon buildup in the cylinders. When this happens the compression is raised because the combustion chamber size is physically reduced and the fuel ignites prematurely because the octane rating in the fuel isn't high enough to prevent it. If you were to run supreme in that same engine it wouldn't ping anymore and the car would actually make a little more power. This would be as a result of the compression increase rather than the fuel...the fuel simply allows the increase to happen by preventing the detonation.
Diesel engines run very high compression like 18:1 and much higher, the only way to prevent detonation is to run a fuel that is very resistant to igniting easily so they use a light oil, or diesel fuel. High compression alone is enough to ignite fuel because compressing air and fuel creates heat and can ignite if the octane rating (ignition/flash point) was low enough to allow it. This is also the reason why diesels don't use spark plugs to ignite the mixture, they use glow plugs which simply add heat to the combustion process and allow the fuel to ignite.
So the bottom line is that if your engine only requires regular octane fuel, it's probably because its stock compression ratio and timing curve is designed to work best with a fuel that ignites at a specific point. Running a premium fuel in the same engine will slightly delay the ignition of the fuel and the speed of the burn. The end result is similar to retarding the engine timing on the car slightly and a potential loss of power. Now todays computer controlled cars are pretty sophisticated and limit what happens internally in the engine and what we feel in the seat of the pants, but essentially what I said is true.
Totally incorrect. Octane has got nothing to do with how 'clean' it burns. Higher octane gas actually burns slower than lower octane gas.</TD></TR></TABLE>
Exactly right. All Octane does is raise the ignition point of the fuel which allows a car that is running higher compression or a more agressive ignition curve to make more power. I'm sure you've all heard an older car "pinging" while going up hill or cruising on the highway while under load. That's called pre-ignition or detonation and it comes from excess carbon buildup in the cylinders. When this happens the compression is raised because the combustion chamber size is physically reduced and the fuel ignites prematurely because the octane rating in the fuel isn't high enough to prevent it. If you were to run supreme in that same engine it wouldn't ping anymore and the car would actually make a little more power. This would be as a result of the compression increase rather than the fuel...the fuel simply allows the increase to happen by preventing the detonation.
Diesel engines run very high compression like 18:1 and much higher, the only way to prevent detonation is to run a fuel that is very resistant to igniting easily so they use a light oil, or diesel fuel. High compression alone is enough to ignite fuel because compressing air and fuel creates heat and can ignite if the octane rating (ignition/flash point) was low enough to allow it. This is also the reason why diesels don't use spark plugs to ignite the mixture, they use glow plugs which simply add heat to the combustion process and allow the fuel to ignite.
So the bottom line is that if your engine only requires regular octane fuel, it's probably because its stock compression ratio and timing curve is designed to work best with a fuel that ignites at a specific point. Running a premium fuel in the same engine will slightly delay the ignition of the fuel and the speed of the burn. The end result is similar to retarding the engine timing on the car slightly and a potential loss of power. Now todays computer controlled cars are pretty sophisticated and limit what happens internally in the engine and what we feel in the seat of the pants, but essentially what I said is true.
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From: Trackside with the smoking bee
Re: (dantastic)
00Red_SiR...wonderful response...
This is why B16's and B18C's require premium gas, because they have higher compression ratio's and need a higher octane rating to resist detonation. If your compression ratio is over 10:1 and/or you are boosted, you should be using the highest octane fuel you can (detonation under boost is even worse than detonation under NA).
This is why B16's and B18C's require premium gas, because they have higher compression ratio's and need a higher octane rating to resist detonation. If your compression ratio is over 10:1 and/or you are boosted, you should be using the highest octane fuel you can (detonation under boost is even worse than detonation under NA).
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