87 octane in HEMI = Trouble
#11
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That's why I didn't understand. Your logic is backwards.
Did you read what I posted? A higher Octane that you purchase from the gas station can no way in hell be bad for your engine. Higher octane can only do good. Whether it's needed or not is another thing. In the Hemi's case...89 should be the lowest anyone is running. Now if your solely a highway driver and on flat level ground and don't bog the engine down, 87 is do-able.
Here's a quick lesson... The Northstar engine GM produced for the Cadillac's requires 91octane. if you put 93octane you cannot do any harm to the engine. if you put in 87 or 89 octane you will damage the engine. octane is a one way streak. You can always go up, but you can never go down. Hope this helps.
Did you read what I posted? A higher Octane that you purchase from the gas station can no way in hell be bad for your engine. Higher octane can only do good. Whether it's needed or not is another thing. In the Hemi's case...89 should be the lowest anyone is running. Now if your solely a highway driver and on flat level ground and don't bog the engine down, 87 is do-able.
Here's a quick lesson... The Northstar engine GM produced for the Cadillac's requires 91octane. if you put 93octane you cannot do any harm to the engine. if you put in 87 or 89 octane you will damage the engine. octane is a one way streak. You can always go up, but you can never go down. Hope this helps.
#12
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right, when i first read the post it reminded me how a lot of people on the forum were posting about going up in octane ratings and thats basically how it got me on that topic of the higher octane rating, sorry for the confusion!
Last edited by 02Steve1990; 04-12-2009 at 11:05 AM.
#13
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Yeah, I gotta admit, I'm kinda lost on this one too.
Also, I can't see how a clogged EGR, a normal occurrence over time, no matter what octane you use, resulted in a $600 repair bill. Sounds to me like your mechanic kinda "saw you coming".
Although personally, I fail to see how someone can justify NOT spending an extra 20 cents or so a gallon on a $30k+ investment. When a manufacturer "recommends" a certain grade of fuel, you need to just swell up and use it.
The only time I'd consider 87 octane is if the manufacturer states that the engine is specifically designed for 87 and you will get NO benefit from a higher octane fuel.
Also, I can't see how a clogged EGR, a normal occurrence over time, no matter what octane you use, resulted in a $600 repair bill. Sounds to me like your mechanic kinda "saw you coming".
Although personally, I fail to see how someone can justify NOT spending an extra 20 cents or so a gallon on a $30k+ investment. When a manufacturer "recommends" a certain grade of fuel, you need to just swell up and use it.
The only time I'd consider 87 octane is if the manufacturer states that the engine is specifically designed for 87 and you will get NO benefit from a higher octane fuel.
#14
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i ran 87 in mine for one summer. then it started running rough and got CELs. took it to the dealer under warranty, and i had predetonation in 2 cylinders, burning holes right thru them calling for an overhaul and teardown. all covered under warranty, but the dealer said running at least 89 in it would prevent it in the future. so i do. too many potential problems tryin to save so little money on 87.
#15
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the hemis also had problems with the egrs going bad. I had to replace the one on my truck and when i worked at the dodge dealer I replaced tons of them. so the egr problem he had was not actually from the lower octane fuel but you do need to run the higher to keep from detonating your motor. dodge recommends at least 89 octane but 91 will definitely help keep it cleaned out.
#16
#17
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the hemis also had problems with the egrs going bad. I had to replace the one on my truck and when i worked at the dodge dealer I replaced tons of them. so the egr problem he had was not actually from the lower octane fuel but you do need to run the higher to keep from detonating your motor. dodge recommends at least 89 octane but 91 will definitely help keep it cleaned out.
EGR problem can be from lower grade fuel. here's how: Lower octane fuel is very dirty in an engine that is prone to detonation because of the lower grade fuel. Detonation causes lots of unburned fuel and carbon build-up inside the engine. This contributes to faster than usual build-up. Thus why i said higher octane causes less pollutants in an engine because most of the fuel is burnt with very little if anything left behind as deposits.
Babied or *****-footed vehicle can have the same problem. The owner never goes up into the higher rpms often enough to burn or cleanse the engine of all the deposits. A hotter engine is usually a cleaner engine. Usually. I feel (my opinion here)that stock tunes cause more problems than good because of their restrictions with emissions and eagerness to please the EPA. A tuner can solve a lot of these issue's and keep your engine cleaner even when "babying it".
I never baby my vehicles when i drive them, nor do i purposely beat the crap out of them. I keep my mainenance schedule ahead of the manufacturer at all times and haven't had any problem in any vehicles I have ever owned! Ever! Never a tranny problem, never an evgine problem, never been broken down. I am always one step ahead of the manufacturer reccomendations.
Not directly related, but it kinda is...???...lol
#18
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Babied or *****-footed vehicle can have the same problem. The owner never goes up into the higher rpms often enough to burn or cleanse the engine of all the deposits. A hotter engine is usually a cleaner engine. Usually. I feel (my opinion here)that stock tunes cause more problems than good because of their restrictions with emissions and eagerness to please the EPA. A tuner can solve a lot of these issue's and keep your engine cleaner even when "babying it".
just recently i have set my hypertech to the 91 setting and running premium fuel. it runs sooo much nicer, better response, etc. hope it helps the buildup problem, plus i know im free n clear of predetonation now as well. My local dealer, after overhauling and rebuilding my engine under warranty, could not stress enough to me that the hemi NEEDS 89 or higher to run without doing damage.
#19
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the hemis also had problems with the egrs going bad. I had to replace the one on my truck and when i worked at the dodge dealer I replaced tons of them. so the egr problem he had was not actually from the lower octane fuel but you do need to run the higher to keep from detonating your motor. dodge recommends at least 89 octane but 91 will definitely help keep it cleaned out.
#20