LOL - you lost me there. Have you got any idea what octane means?

 

Yes I do, ethanol burns quicker and causes predetonation in a gasoline engine, hence why I say it's like 85/86oct. Octane ratings are very indepth and to simplify things, i wont go there.
We all know 100% gasoline runs better than gas mixed with ethanol on a gas tune!

 

Octane means the rating of gasoline is a measure of its resistance to "knocking". Knocking is the result of the air/fuel mixture in a cylinder burning before the spark plug fires (pre-ignition) or of the mixture burning too rapidly or unevenly (detonation). The octane rating is a measure of how much heat is required to get the fuel to burn.

The octane rating is not a measure of how much energy is contained in the fuel. However, engines that are designed to use higher-octane fuel can produce more power due to the use, for example, of a higher compression ratio or through the use of a supercharger or a turbocharger. Compression is directly related to power, so engines that can compress the mixture to a greater degree deliver more power. Since the higher octane fuel/air mixture can be compressed more before knocking results, it allows more aggressive engine designs and calibrations that can extract more power from each gallon of gasoline.

Octane is a hydrocarbon that is one product of refining crude oil. A molecule of octane contains eight carbon atoms and 18 hydrogen atoms. Interestingly, automotive fuel may actually contain no octane because it is very expensive. Octane is exceptionally resistant to exploding spontaneously when exposed to the heat and pressure found inside a typical combustion chamber. Heptane is another hydrocarbon product of refining crude oil. A molecule of heptane contains seven carbon atoms and 16 hydrogen atoms. However, unlike octane, heptane is highly susceptible to such self-ignition.

 

Yeah, they would NEVER risk poor word of mouth. They only knew about cracked dash issues for what, a dozen years and the LSDs still break off clips that explode rear differentials and have been doing so since the 2nd Gens came out with AAM rear axles in '94.

You are making the assumption that a major corporation would operate in a logical fashion. Bad assumption, IMO.

Like I've stated, I personally know guys with Hemi trucks with 150k + on them who have never run anything but 87 octane. BUT in EVERY case that I have seen or talked to someone who had a cylinder or multiple cylinder failures, the person has at some point "fessed up" to running 87 octane, even if just to me and "off the record".

EVERY tuner manufacturer cautions against running a lower octane fuel than the tune is written for - citing that irreparable engine damage can result.

If you want to run 87 because the manual says it's "ok" - fine. Understand you'll be running a "de-tuned" engine and I think your risk of engine problems will be significantly higher, but over-all I think unless you haul/tow or push the truck this risk still isn't real high. But I think running a performance tuned engine on a lower grade of fuel than the tuner manufacturer stipulates is just down-right stupid and you deserve what you get.

I run 93 octane exclusively and if I cannot get ethanol-free gas, then it's treated with Star-Tron. I run a 91 octane minimum tune on a fairly highly performance modded truck. If my truck was stock on a stock tune, I wouldn't spend the money on 91/93 octane, but I'd run 89 and still either buy ethanol-free or treat for ethanol...

 

Dont meen to **** in anybodys cornflakes here, but gasoline loose`s octane while sitting in the gas station tanks. So concidering how high the price of gasoline is today, how many people are actually buying 89 octane rated gas right now. Most will buy the 87 octane because .10 cents more for a gallon for 89 octane today dosent make any sense to them. (i certainly agree, but read on) Sooooo, now that alot of people are avoiding the higher priced 89 octane and some of us are knowing how long it has been sitting in the tanks of the gas stations loosing octane everyday, yet some of you guys pull right up to the pump and fill up on old dead 89 octane gas. I myself have been in the middle of some of these gas & octane wars myself, i have used 87 octane on every hemi vehicle i`ve owned since 2003, never had an engine issue ever. (sold my first hemi truck with over 200,000 miles on it, no issues) I get an average 22 to 23 mpg on 87 octane as well with my 2010 hemi 4x4 QC truck. My mpg`s were actually worse when i`ve run 89 octane. I likely lost mpg`s probably because the 89 octane had been sitting a long time in the gas station tanks, likely ended up as low as 80+ octane in some case`s because it sat to long at the gas station. If you couldnt burn 87 octane in these trucks, then i`m sure it would have said so in the manual. As for gasoline being clean, all gas stations have filters on their pumps today, pretty much mandatory nationwide. One more thing to concider... buy your gas at the busiest station, the gas is always fresher due to the volume of sales everyday. I also read in here somewhere where one person said that ethanol lowers octane, that is NOT true. Ethanol actually raise`s octane when mixed with gasoline last time i checked out that information. If i`m wrong, show me the proof (and post it in here) and i will stand corrected.

 

Yep, pure ethanol has an octane rating of about 110, so adding ethanol will raise the octane rating of gasoline. 10% ethanol blend allows oil companies to start with a lower grade of gas, as low as about 84 octane to obtain the 87 octane regular unleaded fuel at the pump.

As far as gas "sitting", I don't know about where you are, but I have family members who owned gas stations for years when there were true "service stations" and they got two deliveries of gas per week. That doesn't leave much time for gas to lose it's octane.

One of the many problems with ethanol is it causes phase separation in gasoline, whereas it absorbs water, mostly in the form of environmental humidity. Non-ethanol gas will not appreciably lose octane for about 90-110 day but 10% ethanol gas will drop about 4 octane points in about 30 days. So by purchasing your E10 gas that has sat for about a month, you could be running 83 octane in your tank.

I do a good bit of small engine repair, you ever notice how often you need to replace the primer bulb or plastic fuel lines or rebuild carbs in seldom used outdoor equipment when 15-20 years ago you never had to? One word - ethanol. I run Star Tron in all my gas, especially my boat and yard equipment gas just as soon as I purchase it unless it's ethanol free...

 

Couple thoughts on ethanol
When it gets introduced to a new area of the country it causes all sorts of problems - for 4 reasons.
1) It is a very good cleaner and it flushes all of the crap out of your fuel system really quickly.
2) It eats certain types of rubber that they havn't used in fuel systems for about 20 years. It also eats fiberglass fuel tanks that exist in some really old boats.
3) Old service stations and marinas have a crapload of water in their tanks, when you add ethanol it will absorb it. Ethanol doesn't absorb any appreciable water when it is in your gas tank unless you are dumping water into your tank.
4) Its got less energy per gallon - which means if you have carburated motors they are going to run lean unless you adjust your mixture, fuel injection doesn't much care.

Once you get over the hump of sorting out these things, you rarely ever hear of an ethanol problem. Ethanol treatment makes me laugh, we've had ethanol gas in MN for over 20 years and you sure don't need to treat it. I run it in my carburated boats and all of my small power equipment (which has been properly adjusted)

 

My truck has ran 87 octane for nearly 31000 miles. No issues

 

85 octane? I hear its the best.

 

Save that load of horse hockey for someone who doesn't do engine repair. I'd say 40% of problems I see are ethanol related. You don't work for the government, do you?

Now granted in THIS section, you'll see next to no major problems from ethanol as by 2007 internals and lines had to be made to resist ethanol, but I've seen MANY gaskets, lines, etc. completely eaten away by ethanol in vehicles as new as '05.

By the way, between 2nd Gen and 3rd Gen owners I have compiled data of over 200 vehicles who have switched to ethanol free or are treating their E10 gas with one of about four products. Seeing about a 15% increase in fuel economy.

I quote this from a recent article on the subject:

“There is no massive PR machine working to point out the downsides of ethanol, like there is on the other side,” said Christa Westerberg, a lawyer in Stoughton, Wis., who has represented opponents of ethanol plants in Wisconsin.


Rick Kitchings, the mechanic in Georgia, said consumers simply should insist on pure gasoline for their small utility engines.
“Theoretically, avoid ethanol,” he said. “Avoid ethanol.”