92 octane vs. 91 octane
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The higher the altitude the lower the octane. In Amarillo, Tx. where I'm at the highest you can buy is 90. I understand that in the mountains premium is 87. The closer to sea level the higher the octane allowed. Barometric pressure or something I don't understand. Explained to me by a gas distributer in the area when I went looking for 93.
91 is the normal premium here in KC. Occassionally I find a BP station with 92. I drove fifteen miles down the freeway last Saturday to a Phillips 66 Truck Stop and put 10 gallons of 100 octane @ $3.99 per gallon. Just wanted to see what it did. I think it's a little faster but don't really know for sure. It doesn't start up as fast as with the 92 but it looks like it's getting a little better gas mileage and, needless to say, I have my foot to the floor as often as possible. I saw a review of gasolines on the web somewhere and they tested 87 using octane additives and then 102 (or somewhere in there) and there was a world of difference in the hp. The higher octane fuel gained 5 to 10 hp more than the 87 with the additive and they were able to manually advance the timing a lot further with the 102. The point was that the higher octane fuel was just an all around better gasoline.
I think people are mis understanding what octane means to you! If you have a high compression engine higher octane is benificial to a certain point. In an old 60's high compression car with no computer management if you could not get the proper octain gas your car would knock or pre ignite the fuel in the cylinder before the spark plug ignited it very bad, but you could manually retard the timing advance to reduce or eliminate the problem! and also reduce performance, move forward to the gto it has an electronic system in place to compensate for lower than optimum octane and retards timing so your car runs without knocking but at a lower performance level. The trick is to buy the octane level that will allow your GTO to run with no knock retard thus obtaining maximum performance! IMO 91 octane in california is slightly to low to allow full performance the car runs but not to its true potential! on the other hand 100 octane is more than likley to much and does nothing more than 93/94 octane other than cost more! You are not being nice to your car by buying higher octane than your car requires! As the octane number increases all it means is that you can squeeze the air fuel mixture tighter before it pre ignites and damages the engine. years ago the oil companies used to only put the good additives into their premium gasolines! since the early 70' federal law has mandated these additives in all fuel grades.
Robert
Robert
Thanks for the info. Even though I hadn't intended to fill up every week with 100 octane fuel, I won't do it again as I definitely don't want to hurt my engine. 92 octane is the best I can find here in KC so that will just have to do. As I had mentioned, I wasn't really sure I could tell any difference in the performance with the 100 octane anyway. With your explanation, I now know I more than likely wasn't. In the reference article I read about the octane additive, they kept advancing and retarding the timing when they changed the fuel so they were probably experimenting on an older muscle car without all the computers.
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So what will happen if you use 87 octane in the GTO?? Gas over here in Vegas is very expensive. $2.30 for premium. Does using 87 octane with additive good for the engine?
If you put in 87 Octane, just make sure the engine is not knocking. There will be a slight degredation in performance from the lower octane as the computer will have to retard timing a little to compensate. However, it should retard the timing and there should not be any knocking. BUT, if it does knock, you definately will want to go to a higher grade.Tuxedo Mask said:
I see no real problem with using 87 and an additive, but is it really that much cheaper than buying the higher grade right at the station? (serious question, I have no idea how much those octane booster additives cost).
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I am not too sure how much the additive cost. I am just asking because it seems here in Vegas that gas prices are rising almost at an hourly rate. Regular unleaded is at 2.20!!!!! i put in about 15 bucks yesterday and it only filled up about 1/4 tank. So if i put in 87 for the time being i will be okay?Neo-GTO said:
Your engine should run ok on 87 Octane, but pay close attention to it and make sure it doesn't begin to knock. If it doesn't knock, you are ok. If it begins to knock, get octane booster and dump it in. It shouldn't knock because the engine should be able to compensate.Tuxedo Mask said:
87 octane
If you decide to try 87 octane drive up a slight incline with light throttle and listen carefully for knocking or pinging! The price you may pay is melted or a hole in your pistons! In my corvette (same engine as GTO Ls1) my ex wife put in a few gallons of regular 87 in an empty tank, when she got home told me the car was running awful and shaking alot! Sure enough it was running poorly drove to the gas station and filled her up with premium helped smooth out the idle quite a bit but still not normal, car has only seen premium since! Oh seemes to me here in Ca premium has gone up .25 in the last ten days 2.45 to 2.50 a gallon
If you go to the corvette forum and do a search there is lots of information on octane,octane boosters ect.
If you decide to try 87 octane drive up a slight incline with light throttle and listen carefully for knocking or pinging! The price you may pay is melted or a hole in your pistons! In my corvette (same engine as GTO Ls1) my ex wife put in a few gallons of regular 87 in an empty tank, when she got home told me the car was running awful and shaking alot! Sure enough it was running poorly drove to the gas station and filled her up with premium helped smooth out the idle quite a bit but still not normal, car has only seen premium since! Oh seemes to me here in Ca premium has gone up .25 in the last ten days 2.45 to 2.50 a gallon
If you go to the corvette forum and do a search there is lots of information on octane,octane boosters ect.
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Well, looks like it's gonna have to be peanut butter and jelly sandwiches from now. i didnt realize that using premium is a must with this car. i am going to give this car a couple of months...if it takes too much money from me.....i will trade in the car.
Don't do it!!!!!!!!!!
Also think about the trade in hit you would take! Keep the car enjoy! Don't do it.
Robert
Look premium is about .20 a gallon more if you were to buy 1,000 gallons of gas a year good for at worst 15,000 miles or 21,000 miles if you drive thrifty by coasting to red lights ect it will cost you $200.00 extra a year about $17 a month extra. My fiancee gets about 18 mi /gal in her 6 speed avg, I think she can do better if she would up shift to 5th faster. my vette averages 20-21 mpg overall, at 80 mph on a 600 mile round trip to vegas I get 29.8 mpg.Tuxedo Mask said:
Also think about the trade in hit you would take! Keep the car enjoy! Don't do it.
Robert
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Oh trust me, i love the car. Right from starting the ignition, you can tell the car has some power. But right now, i guess it depends on the freakin price of oil per barrel. Gas is going way high and it seems like no end in sight. i was thinking of trading it in for a G6....ONLY IF I HAD TO!TORRIDONE said:
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Wow, $2.39 for premium gasoline in 2004!!! I wish. 93 Sunoco Octane is costing me over $3. Some interesting old posts.
2.30!?, we have 3.16 over in jersey
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