Higher Octane = Better MPG?
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Higher Octane = Better MPG?
I was talking to one of my dad's mechanics the other day and the subject of octanes of fuel came up. He told me that the higer the octane, the more energy you get per stroke meaning it burns slower then regular?? Anyone ever heard of this or know the truth about the octanes?
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but if your motor does not have the higher compression to act with the higher energy then its usless..i did this little test my self on a trip to miami i got 31 Mpg on 87 then on the way back full with 93"and seemed to run alill rougher"got 27 mpg fully stock d16z6 automatic
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175+served in engines built from minime to gsr/lsvtec,b16 b20vtec,d15 k24 powerhouses or just rebuilds.life is good
i like when people don't take my advice.cause then i make more money when u need it rebuild the right way!
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i love AUTOZONE
MY CAR iS PROTECTED BY ZOOMBAK GPS LOCATOR IS YOURS?
175+served in engines built from minime to gsr/lsvtec,b16 b20vtec,d15 k24 powerhouses or just rebuilds.life is good
i like when people don't take my advice.cause then i make more money when u need it rebuild the right way!
how many speed holes do i need in my bumper,b4 i can run 15's?
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Here's a reference from another forum which relates to an SRT-4 but some of the info is universal...
Just a quick note .. the octane of the gas will not change your airfuel ratio. This is a simple math function of a quantity of air and a length of time you keep the injector open (sic. specific volume of fuel) in your intake charge. I think I know what you are getting at though.
What you need to alter with the race gas isnt boost or AF, it's timing. The higher the octane the gas is, the slower it burns. You need to advance the timing to make use of this slower burn. If you cannot change the timing then using a higher grade gas will net you little, unless your computer is pulling timing due to knock. Higher octane gas, since it burns slower knocks less cause its a bit harder to light (really *basicly* speaking). I suggest using premium and building to that then treating your car to a couple gallons to 5 of good stuff to raise the octane enough to deal with any knock you might be getting due to higher temps while racing.
Racing gas is expensive and wont really get you a bunch, with the stock computer. But sut sure does smell good out the tailpipe =]
David
What you need to alter with the race gas isnt boost or AF, it's timing. The higher the octane the gas is, the slower it burns. You need to advance the timing to make use of this slower burn. If you cannot change the timing then using a higher grade gas will net you little, unless your computer is pulling timing due to knock. Higher octane gas, since it burns slower knocks less cause its a bit harder to light (really *basicly* speaking). I suggest using premium and building to that then treating your car to a couple gallons to 5 of good stuff to raise the octane enough to deal with any knock you might be getting due to higher temps while racing.
Racing gas is expensive and wont really get you a bunch, with the stock computer. But sut sure does smell good out the tailpipe =]
David
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but if your motor does not have the higher compression to act with the higher energy then its usless..i did this little test my self on a trip to miami i got 31 Mpg on 87 then on the way back full with 93"and seemed to run alill rougher"got 27 mpg fully stock d16z6 automatic
The only way to do a true test is by calculating it at the same average speed and same distance. A trip from here to Miami varies coming and going being that depends on the traffic, how many times you let off the gas pedal and for what distance were you doing a different speed. Also depends on where exactly you got gas at... some gas companies add/take away some additives versus others. This will hinder performance and mileage as well.
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89 is a rip off.
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Originally Posted by P057
"Wow I had a hard time understanding that... but from what I gather you found an open-box item that wasn't cheaper. You bought it anyways. You then called someone a dumbass while making fun of their misfortune of losing a job as you were leaving the store?
I'm surprised you were able to get out the store with that big "SUCKER" sign affixed to your back. "
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Originally Posted by P057
"Wow I had a hard time understanding that... but from what I gather you found an open-box item that wasn't cheaper. You bought it anyways. You then called someone a dumbass while making fun of their misfortune of losing a job as you were leaving the store?
I'm surprised you were able to get out the store with that big "SUCKER" sign affixed to your back. "
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What it boils down to is the cars performance aspects. Look at the user manual in your glovebox and see what it states. Some say run 87... some say run 87 or 89... some say run 87-93 ...some say to run premium fuel only 93 and some say unleaded fuel only. Some cars perform well on 87 and some don't. All depends on the car, size engine, what it was designed for. Remember there's economy cars which were probably designed for the use of 87. I've had cars in the past that performed well with 87 and I had cars in the past that simply hated it and ran like crap. So usually when it came down to my non-turbo cars I would put mid-grade 89.
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Another Question is....I usually roll with the windows down but with this summer we're having F**k that...I notice a little bit of a change with the mpg is it really that big a difference with the a/c on?
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In stop and go traffic it is and it is everytime you let off the gas and give it gas. Yes you will lose a bit of gas mileage being that the engine is working a bit harder. You can notice the difference just taking off the light with your AC on and then do it with your AC off.
