93 octane gas

Discussion in '2005 - 2014 Specific V6 Tech' started by brodude2002, Jul 22, 2005.

  1. DAMN! Can a girl get any respect around here? :rlaugh: :rlaugh: :rlaugh: V-6 or V-8. Why jealous? Hahahahahaha.... Thank God I have never posted a pic.

    Is this better.... Hi. Ummm my name is Jennifer and I am a short hottie. I like to drive with my windows open and no A/C. But, my golden Red hair blows in my eyes. Should I wear a hat? or a pony tail? And, should I match my lipstick to my nail polish or to my car color. Please help! :D

    (No disrespect intended to those ladies who are a devoute girlie girls with little to no technical knowledge. I just happen to get the best of both worlds. :owned: )
  2. octane= resistance to detonation

    if you put 87 in a high compression engine, the heat from compression stroke will ignite the a/f mixture before the spark plug fires, detonation. same is true for boosted engines.

    putting 93 into an engine that requires 87 is a waste of money. all your doing is making it harder for the engine to ignite the a/f mixture.

    also a myth that 93 will "clean" the fuel system. all grades have the same amount of detergents. just thought i'd throw that in there


    Now, here is a pop quiz, boys and girls. Do we know what octane means? Where the derivitives of 87/91/93 octane come from and what is the other main component in vehicle fuel? :p
  4. AZ has two types of gas, for summer and for winter i know that much

    MTBE and ethanol depending on what part of the year.

    And the formula to get the octane is....

    "Research Octane Number (RON) and the Motor Octane Number (MON). The formula is RON+MON/2 normally abbreviated as R+M/2 on the pump. "
    i copied that obviously, but in us people terms it basically means an average or mean between the 2 octane ratings (research and motor)
  5. Not always true, a lot of gas stations put more detergents in the higher grade gas. Chevron, QT, among others do not, its the same in all grades.
  6. The name "octane" comes from the following fact: When you take crude oil and "crack" it in a refinery, you end up getting hydrocarbon chains of different lengths. These different chain lengths can then be separated from each other and blended to form different fuels. Octane has eight carbons chained together. Eighty-seven-octane gasoline is gasoline that contains 87-percent octane and 13-percent heptane (or some other combination of fuels that has the same performance of the 87/13 combination of octane/heptane). It spontaneously ignites at a given compression level, and can only be used in engines that do not exceed that compression ratio.

    In winter some states AZ and CA both add MTBE to gas or "oxygenate" it. MTBE is the acronym for methyl tertiary butyl ether, a fairly simple molecule that is created from methanol.

    MTBE gets added to gasoline for two reasons:

    It boosts octane and it is an oxygenate, meaning that it adds oxygen to the reaction when it burns. Ideally, an oxygenate reduces the amount of unburned hydrocarbons and carbon monoxide in the exhaust.

    MTBE started getting added to gasoline thanks to the "Clean Air Act of 1990". Gasoline can contain as much as 10% to 15% MTBE.

    Recent studies on the cancerous aspect of MTBE has prompted some advisory groups to request a replacement additive in lieu of MTBE. The most likely thing to replace MTBE in gasoline is ethanol. It is somewhat more expensive than MTBE, but it is not a cancer threat.

    Faz... YOU PASS. You got the MTBE and Ethenol. I had NO CLUE about the octane rating formula. I was more thinking OCT..meaning 8 for the hydrocarbon chain, but you got extra credit and taught me something new.. WOOT! Which is something I LOVE... :)

    Okay. Anyone want to look into refinery processing and costs of fuel? LOL
  7. Jenn, you're going to cry if you know the refinery costs. And Im hurt Ive gone all this time unnoticed on these boards!

    I most definitely have a manual v6. And it definitely was bought two weeks before they were released public back in last December. *cries some more over all his lost and wasted time on these boards going unnoticed*
  8. No-No Darlin' you time has been noted, monitored and cataloged. :D :rlaugh:

    I asked about your engine as to not have to search around. Just checking. No worries. I'll still respect you in the morning. :D

    As for refinery costs. Thanks for bringing up the point on "COST". We all think that the gas prices are the way they are because the large oil companies are unilateraly setting them and wanted to have an educated discussion with peeps as to where the final cost comes from. :nice:

    Shall we?
  9. Damn. I was actually going to come back and go through the process step by step when I had time, but screw that. Have fun on your own >=(
  10. I use 93 in my '05 GT and I haven't had any problems, it was actually recommended by the dealership surprisingly enough... :shrug: but the Hp gains thing I had no clue about, learn something new everyday!

  11. :( I don't like doing it by myself. :stick:
  12. Why would the dealer recommend 93 when the manual states 87?
  13. Because most dealers/salespersons are not mechanically astute and they would be better opt to sell Mary Kay Cosmetics than cars. :nonono:
  14. Gentlemen and Ladies,

    My Father was an engineer at Exxon for 33 years before he retired. Here is some of the fuel wisdom he relayed to me over the years…

    The previously mentioned characteristic of "octane" referring to resistance to detonation is correct. Will higher octane gas give you more HP and fuel economy? No and Yes. In an engine designed for 87 octane, using a higher value will yeild NO, nada, zip, the-goose-egg, bupkus increase in HP or mileage, in fact, it may even reduce it. However, if your engine's computer is "tuned" for the additional octane (typically by advancing the spark) then the higher octane will give a bit more power. Also, if you go and retune your car to utilize the additional octane, you can't put 87 in it again without risking detonation (knocking/pinging).

    As mentioned, the pump octane rating is the average of the RON (research octane number) and MON (motor octane number). The RON number is significantly higher than the MON due to the testing conditions. The RON is determined while running the engine at constant speed and low engine load. The MON is determined at high rpms and high load conditions. Thus, the MON is more indicative of the engine's requirements during hard/spirited driving (like racing).

    Also note; there is no way to know what the individual values are. For example … an octane rating of 90 on the pump could have a RON/MON of 92/88 or 95/85. I would rather have the 92/88 stuff in my car since the MON value is greater. Detonation will usually occur under "MON-like" operating conditions (fast acceleration and high load) so the 88 MON stuff is better. Unfortunately, the 95/85 stuff is probably cheaper to make so this is what they'll sell.

    The take home message here is to use what the manufacturer specifies, they tend to know a lot about the engines they make (who would have guessed?)
  15. :cheers: <<< Yeah, what he said. :nice:

  16. Dunno, but I have to run out the 93 in my tank before I can put something lesser in it...just a little more to go!