fot 5.13s going to 4.10s Part II
08-04-2008, 02:31 PM
#12
JK Super Freak
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I was Just thinking..... Up here in Canada any gas that has Ethanol is higher octane. i.e. Our regular without Ethanol is 87 Octane, regular with 10% Ethanol is 89 and the same with Premium, without Ethanol its 91 with 10% Ethanol it is 93 Octane. So looking for a fuel without Ethanol isn't doing you any good if you want higher Octane up here in Canada anyway.
That being said, if your vehicle is programmed to run 87 octane and you try and run 93 it will run like crap and visa versa. That may be a good reason why some vehicles do not run well on Ethanol mixed gas.
I had issues with factory ignition programming and poor fuel with my 98 RAM. My findings were that the factory timing etc prefered fuel with a 89+ octane to be consistent. I could run 87, but if the fuel was old or had a little water in it that 5.2L would knock under load. The only alternative was to either run higher octane or reprogram using an aftermarket programer. So, the following is based on some experimenting I did on my 98 Dodge RAM with MAGNUM 5.2L which does not have an anti knock sensor, and a SUPERCHIP programmer. When programmed for 87 Octane regular pump gas, it ran great, no knocking, average power and descent mileage, however if I tried to run higher octane it was very noticeable, it did not run well. Then I reprogrammed for performance and high Octane. It was an animal on high octane and did everything better from off the line starts to pulling trailers up hills. Then I tried reg 87 gas without reprogramming back to 87 and it would knock so bad it would hardly run.
I also have a 2000 Honda ATV that will not run properly on high octane.
So, my point is that maybe the factory tuning of your JK tends to like a little higher octane and that may be why it has more power to climb etc. You may want to try a Hypertech programmer .
Maybe there is a tidbit or two of info here that might help you sort out and understand your situation..
That being said, if your vehicle is programmed to run 87 octane and you try and run 93 it will run like crap and visa versa. That may be a good reason why some vehicles do not run well on Ethanol mixed gas.
I had issues with factory ignition programming and poor fuel with my 98 RAM. My findings were that the factory timing etc prefered fuel with a 89+ octane to be consistent. I could run 87, but if the fuel was old or had a little water in it that 5.2L would knock under load. The only alternative was to either run higher octane or reprogram using an aftermarket programer. So, the following is based on some experimenting I did on my 98 Dodge RAM with MAGNUM 5.2L which does not have an anti knock sensor, and a SUPERCHIP programmer. When programmed for 87 Octane regular pump gas, it ran great, no knocking, average power and descent mileage, however if I tried to run higher octane it was very noticeable, it did not run well. Then I reprogrammed for performance and high Octane. It was an animal on high octane and did everything better from off the line starts to pulling trailers up hills. Then I tried reg 87 gas without reprogramming back to 87 and it would knock so bad it would hardly run.
I also have a 2000 Honda ATV that will not run properly on high octane.
So, my point is that maybe the factory tuning of your JK tends to like a little higher octane and that may be why it has more power to climb etc. You may want to try a Hypertech programmer .
Maybe there is a tidbit or two of info here that might help you sort out and understand your situation..
08-04-2008, 03:00 PM
#13
JK Jedi Master
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OK,
At the advise of my mechanic buddy, before I set the gear shop loose on my rubi, I tried 91 octane NON-ethanol (hard to find non-ethanol in Denver for some reason) just to see if there was a difference.
It is still not quite strong enough to hold 60 up the steep parts of I-70. But its freaking close. Close enough that I believe my money will be better spent finding another few horses. I havent decided how yet. Time for some research.
Also, I dont want to start a whole argument about octane. I have no idea if its the octane or the fact the fuel was actual gasoline and not a mix, or some combination. Maybe my jeep just needed a rest... The bottom line is, she has a touch more power. One more touch and I will be a happy camper.
At the advise of my mechanic buddy, before I set the gear shop loose on my rubi, I tried 91 octane NON-ethanol (hard to find non-ethanol in Denver for some reason) just to see if there was a difference.
It is still not quite strong enough to hold 60 up the steep parts of I-70. But its freaking close. Close enough that I believe my money will be better spent finding another few horses. I havent decided how yet. Time for some research.
Also, I dont want to start a whole argument about octane. I have no idea if its the octane or the fact the fuel was actual gasoline and not a mix, or some combination. Maybe my jeep just needed a rest... The bottom line is, she has a touch more power. One more touch and I will be a happy camper.
08-04-2008, 03:42 PM
#14
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08-04-2008, 03:43 PM
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08-04-2008, 05:24 PM
#16
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Info
ethanol enhanced fuel is basically mandated by the US government thanks to the save the earth politicals in CA. As far as I know, it is being rolled out across the country - no choice. (for reference, I have been in the gas business 20 years and own two gas stations, BUT not the oil business)
Back to the difference in altitude, and its effects on the rating/ fuel.
(reference the wickipedia entry on octane.)
I love mine. Fixed the speedo, and noticably got rid of that dead spot in the gas pedal.
Just trying to learn. I hate buying mid grade just to put in 87 like the om says.(reference the wickipedia entry on octane.)
I love mine. Fixed the speedo, and noticably got rid of that dead spot in the gas pedal.
08-05-2008, 07:06 AM
#17
JK Junkie
wow!! so greggradwohl's mechanic is a moron because he didn't have the right answer all the way, but now Rcjeeper comes up with a very logical explanation, does that make teej a moron? 
I'm just reading this post to see what moron stands at the end 
I'm just reading this post to see what moron stands at the end