GP1138 Posted December 21, 2003 Report Share Posted December 21, 2003 I decided to put some Silver in my tank, and I'm not noticing much of a difference. I do notice a little less rod knock, maybe a small butt dyno perf. increase, but nothing really new. Anyone had any problems switching back to 87 after using 89 or 93? Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted December 22, 2003 Report Share Posted December 22, 2003 rod knock? heck i use 85 all the time with no spark knock. i never noticed a difference with anything higher. of course, the lowest my TGP engine will see is 91; same as my GTS. joshua Quote Link to comment Share on other sites More sharing options...
gp90se Posted December 22, 2003 Report Share Posted December 22, 2003 if u notice a difference between 87 and 89, theres prolly a problem with your engine. i ran 89 in my 3.1 since I got it, I used 87 1ce and my engine wouldnt warm up anywhere near as well as it should have. my father minivan uses 89 becuase it actually knocks with 87. my 3.1 was chipped so thats the main reason I used 89, the 3.4 is going to get 87 till i get to play with it. -Jeff Quote Link to comment Share on other sites More sharing options...
Steve LS Posted December 22, 2003 Report Share Posted December 22, 2003 Save your money, save your hopeful thinking. higher octane is for higher compression engines or forced induction. Wont do anything for a stock production engine. The power is in the engine pieces not the gas. Then if you have raised comp. or turbo/SC you will need higher octane so that it doesnt preignite, thats what octane is all about. Overly advanced timing falls into the picture also, like performance chips. Quote Link to comment Share on other sites More sharing options...
gmrulz4u Posted December 22, 2003 Report Share Posted December 22, 2003 Since we're on the topic of Octane, here's something that I found: Since 2000 I had been running only 91 Octane from the same Shell station. During this time, I would frequently watch my ECM adjust timing via my AutoXray scanner. This past August I decided to go back to 87 Octane and see if I noticed and differences. I also switched from Shell to ESSO and threw in a can of the best fuel injector cleaner-in-a-can, BG 44K. Well, besides noticing that my fuel gauge was now working properly(probably due to the BG 44K), I noticed that my car ran NO different than it had on 91. Absolutely no noises while accelerating or idling or anything, hot or cold. Performance was the exact same, maybe even slightly better. I also wanted to see what my ECM would do to adjust timing now that I was using a lower octane of gas, and to my surprise, it didn't really do ANYTHING!! At the most, the timing is maybe 0.5 degrees less at idle than it was with 91. Whether this really means anything or not is debatable, but I definately thought I was see a few degrees or more difference in the timing of the engine, but I was wrong. Quote Link to comment Share on other sites More sharing options...
OldsmoBeast Posted December 22, 2003 Report Share Posted December 22, 2003 yeah I randomly pick octanes based on how I feel at the pump....no joke...a while ago i used 91, then 89, then 94, then 87, 87 and 94 again today....no differences.... Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted December 22, 2003 Report Share Posted December 22, 2003 good info thanks just wanted to throw another question in - does altitude have anything to do with octane requirements of an engine? i'm wondering if that is why 85 octane is available up in Wyoming? 87 was the lowest i ever seen in when i lived in Minnesota. joshua Quote Link to comment Share on other sites More sharing options...
Shaners Posted December 22, 2003 Report Share Posted December 22, 2003 Unless you have a custom PCM/ECM then you are pissing away your money on premium fuel. I'm running a Westers Garage PCM in my 2500HD, and it requires more octane otherwise I'll get some pinging. My bike is also fuel injected and for a few years I ran nothing but high octane gas in it, but when push comes to shove, the darn thing runs as good or better on 87 Octane!!! MPG's are also just as good... So in my opinion, unless your motor is pretty much worn out, then save your money!!!! There should be "no" seat of the pants feel to running the good stuff. If you wnt seat of the pants results run some good Fuel Injector Cleaner, or top end cleaner through the motor!!! Quote Link to comment Share on other sites More sharing options...
sonyman87 Posted December 22, 2003 Report Share Posted December 22, 2003 Since we're on the topic of Octane, here's something that I found: Since 2000 I had been running only 91 Octane from the same Shell station. During this time, I would frequently watch my ECM adjust timing via my AutoXray scanner. This past August I decided to go back to 87 Octane and see if I noticed and differences. I also switched from Shell to ESSO and threw in a can of the best fuel injector cleaner-in-a-can, BG 44K. Well, besides noticing that my fuel gauge was now working properly(probably due to the BG 44K), I noticed that my car ran NO different than it had on 91. Absolutely no noises while accelerating or idling or anything, hot or cold. Performance was the exact same, maybe even slightly better. I also wanted to see what my ECM would do to adjust timing now that I was using a lower octane of gas, and to my surprise, it didn't really do ANYTHING!! At the most, the timing is maybe 0.5 degrees less at idle than it was with 91. Whether this really means anything or not is debatable, but I definately thought I was see a few degrees or more difference in the timing of the engine, but I was wrong. Timeing verience = Weird.... Could it have been Temperature Related? Gas gages majicly works after cheep gas. sounds like something else or a fluke... If the 87 was Casey's or Texaco or other in that particular chain of gas stations they do NOT use addatives in their fuel so it burns more hot and violently(dosnt make any sence) Shell and Amaco use adatives to make their fuel more efficent(hoax IMO) Those are the only differences between gas stations b/c ALL gas companys get their gas from the same local/distant distributor. i hope i didn't confuse anyone... Quote Link to comment Share on other sites More sharing options...
Bolt_Crank Posted December 22, 2003 Report Share Posted December 22, 2003 my car throws code 43 whever I run 87 octane, and the car runs almost like ass, on 89 it runs great Quote Link to comment Share on other sites More sharing options...
gmrulz4u Posted December 22, 2003 Report Share Posted December 22, 2003 my car throws code 43 whever I run 87 octane, and the car runs almost like ass, on 89 it runs great So then your car has a problem...assuming that what your engine is doing is "normal" would be completely wrong... Quote Link to comment Share on other sites More sharing options...
Bolt_Crank Posted December 22, 2003 Report Share Posted December 22, 2003 I know it's got a problem, but, it runs perfect... except for the IAC not liking the cold, and the injectors making noise. Quote Link to comment Share on other sites More sharing options...
gmrulz4u Posted December 22, 2003 Report Share Posted December 22, 2003 Well your timing is probably just way over advanced. This could be caused by a few different things, one of them being the Knock Sensor. Quote Link to comment Share on other sites More sharing options...
Bolt_Crank Posted December 22, 2003 Report Share Posted December 22, 2003 well, that's what code 43 is... a problem with the knock sensor, but it doesn't throw that code anymore Quote Link to comment Share on other sites More sharing options...
WhiteOut Posted December 23, 2003 Report Share Posted December 23, 2003 There's no extra power in higher octane fuel. In fact high octane fuel is slightly less dense, and less explosive under STP conditions. Thus it follows that the heat of combustion is slightly less (i.e less energy) per mole of gasoline in high octane fuel as compared to regular gasoline. I suspect that anyone who sees a performance increase is actually seeing the effect of the extra addatives present in the premium gasoline which serve to clean the injectors, ports, etc...because from a purely chemical/scientific point of view there should be a slight decrease in performance since the higher octane gasoline is less volatile. Quote Link to comment Share on other sites More sharing options...
92turboLE Posted December 23, 2003 Report Share Posted December 23, 2003 Unless you have a custom PCM/ECM then you are pissing away your money on premium fuel. Not true... it is actually cheaper in the long run due to gas mileage. I didnt belive it, but i ran the numbers on it after 5 or so tankfuls and i was actually saving money. Off 85 octaine, i was getting anywhere between 15-22 mpg depending on how i drive, and with the 91, im getting roughly 18-27 mpg. My engine runs much smoother as well. i did the math and for me (i drive ALOT) i was saving around $35 a month in gas and still driving about the same amount. sometimes more in the winter just to find good snowy spots to play on, lol, not to mention the shitty milage due to the fact that im spinning my tires alot on the snow (on purpose of course). - Justin Quote Link to comment Share on other sites More sharing options...
gmrulz4u Posted December 23, 2003 Report Share Posted December 23, 2003 i did the math and for me... That's the important thing here, these were YOUR results, not everyones. I'm come to realize that a lot of things I learn about MY car, more than half the time are NOT the "norm". Quote Link to comment Share on other sites More sharing options...
Steve LS Posted December 23, 2003 Report Share Posted December 23, 2003 92turboLE - you have forced induction, you need high octane. Without it your knock sensors are retarding your timeing and your engine is not running to its efficency, your milage would drop, not sure if as much as 3-5 MPG. I can vary my MPG's by 5 or more with just driving habits. On a NA or low compression engine octane wont make a difference. High octane is for performance motors thats why they had to make so many gas options. The old high compression GM engines, like 10.2:1 or 10.5:1 wont even run without pinging on todays 93 octane. 9.5 is about it for 93. - - Though with the use of 2 knock sensors the SII 3800 has 10:1 I think ?. I had a 12.5:1 back around 1980 when we still had 96 Sunoco and I had to set my timing at TDC and feed gas smoothly instead of punchin it or it would still ping. Bought avation gas once and it really ran, big difference and I did not set my timing up to where it should be. This was only because of the compression the pistons made. The higher octane gas resists firing too soon because of the heat created by the compression. At 8.5:1 93 octane does nothing but explode and push the piston down just like any other gas would. But maybe less as WhiteOut explains because its not compressed like racing pistons or Turbo/Supercharger does. Now if you compress that higher octane its a whole nother beast. Canadian BA - I use high octane for my sitters because gas gets stale. Not sure if higher octane is the answer though. Gas is clean period, if you ever washed parts in it you'd know. Like we used to before we grew brains or was it decided to save what little was left after the fumigation. :shock: I have never needed to use injector cleaner, though I have tried it to "fix" a problem, which it never did. Just hopeful thinking. Nothing should get passed a fuel filter that can't go through the injectors or be burned anyhow. If you doubt it pull your injector rail and notice how sparklin clean it is inside. Big money in additives, why do you think everyone and everyone that hasnt yet makes or will make them. Their just selling wishful thinkin - miracles in a can - honest politicians - Florida snowbelt - deep sea fishing in Montana Quote Link to comment Share on other sites More sharing options...
92turboLE Posted December 23, 2003 Report Share Posted December 23, 2003 92turboLE - you have forced induction, you need high octane. Without it your knock sensors are retarding your timeing and your engine is not running to its efficency, your milage would drop, not sure if as much as 3-5 MPG. I can vary my MPG's by 5 or more with just driving habits. I DO????? :shock: :shock: :shock: lolz, actually i dont... YET! high octaine does actually increase gas milage. whoever said that those were MY results, your aboslutely right, but it seems to be consistant through everyone i know here that runs it... by running high octaine, the fuel actually burns slower and more consistant and thurogh (sp?), producing more power, therefore you motor does not have to work quite as hard and will get up to speed quicker. It may not be a very noticable difference at first, but just from what i have seen in my own and many other peoples cars, after a few tanks ful, it is a very noticable difference. - [announcer voice]Individual results may vary[/announcer voice] thats just my $0.02 though. bottom line, im convinced and now religiously use the highest octain pump gas i can get (91 usually unless im feeling adventurous and drive a little bit to get 93.5) - Justin Quote Link to comment Share on other sites More sharing options...
gimp19 Posted December 24, 2003 Report Share Posted December 24, 2003 I just use what the manual says to. In my Cutlass I use 87 and have no problems at all. In my LT1's I use 91 or 93 depending on how much $$ I have cause the manual suggests higher octane in those motors. Quote Link to comment Share on other sites More sharing options...
Steve LS Posted December 24, 2003 Report Share Posted December 24, 2003 TURBO ? ? ? Oh well, like I said " Their just selling wishful thinkin - miracles in a can - honest politicians - Florida snowbelt - deep sea fishing in Montana" Just a few tanks ey ? What ? Does the engine get used to it ? Does it clean up all those dirty little things and that causes less friction ? Does that high octane fuel that burns SLOWER and more EVENLY have time at 22 hundred revolution per minute - thats 36.66 revolutions per second to realize ITS BRUTE STRENGHT and slow even burning EXTREME EFFECIENCY ? Geese if I could only get race gas for the L67 I'd get 32 MPG highway instead of the 27. I know I sound harsh but maybe you should try switching back to 87 for a few tanks and keep your foot out of it trying to see if theres more or less power and get accurate mileage results. I switched to 92/93 years ago pulling a UHaul down to NC with my Dakota. After 2 tanks I realized I was throwing money at people that dont deserve it. I had no more power and got if memory serves me 22-23 consistently. Quote Link to comment Share on other sites More sharing options...
WhiteOut Posted December 24, 2003 Report Share Posted December 24, 2003 I'm with Steve LS on this one, it doesn't seem to matter what I put in the tank I get the same mileage regardless, and I've tried the whole "it takes a couple tanks" thing. Result...nothing...well nothing but slightly worse gas mileage, and we'll attribute that to the lead foot which is also by the way not getting me any better gas mileage despite lead's ability to increase octane. Quote Link to comment Share on other sites More sharing options...
getragz34 Posted December 24, 2003 Report Share Posted December 24, 2003 Our cars and most production cars will run fine with 87 Octane. I also have a SuperChip in my car and I run 87 Octane, runs pretty good. If your always driving around the city in stop and go traffic and hardly get on the highway I would recomend a higher Octane once and awhile. Just for the simple fact that it burns a little bit cleaner and therefore your engine will run cleaner. With lower octane there is more build up of carbon, which is not good for your engine. If you do a constant highway driving, then changing to a high Octane is a waste of money and will do nothing for performance. Injector cleaners are also a waste of money. In some injector cleaners, they have a product called Methyl Hydrate and another one that I can't remember. These products are not well suited for fuel injected cars. The chemicals used to clean your injectors also harm the injectors, by making the nozzle larger therefore bad mixture. Must be carefule also with fuel additives that are used for storing your vehicle as well. Just my tip for the day Ciao Quote Link to comment Share on other sites More sharing options...
4spdz34 Posted December 24, 2003 Report Share Posted December 24, 2003 my dads 355 camaro runs 93 octane in it and it has 11.9:1 compression, the timing is set a 30* advanced and it does not ping, amoco gas. i have the ffp chip in my car and my new motor has a estimated 10.25:1 compression. anyone know of any good caclulators for the compression? i had the heads shaved .025 and the head gaskets are .020 thinner than stock. the guy at the head shop told me i woul gain one point in compression. well anyway i have just over a 100 miles on that motor and i put in 89 last night ( i usually use 87) and it made a difference for me. Quote Link to comment Share on other sites More sharing options...
GPdriver1986 Posted December 24, 2003 Report Share Posted December 24, 2003 Higher Octane does not do anything if your car is stock or some kind of high preformance car. My auto teacher explained it this way if you put high octance in a stock Cavalier it will run normally, but if you put low octane gas in a Corvette it will run like crap. Quote Link to comment Share on other sites More sharing options...
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