I was just wondering if all of you use 93 or 87 on LO3s? (LO3s or other tbi motors only) I have always pumped 93 in my firebird but i was reading over the questions and answers that ShiftyCapone wrote and it says that not really needed to run high octane on tbis and makes no diffrence. (on a stock or mostly stock tbi that is) I believe ShiftyCapone and that does make a lot of since. I was just wondering what everybody else runs. Thanks. (oh by the way i want to thank ShiftyCapone for the questions and answers, it has help me out ALOT on few things i had been wondering about)

 

Its all based on compression and timing. On a stock L03 using 93 may lead to loss in a power and excessive carbon build up. Just not worth it. Good idea to run 87.

 

i always ran 87. 93 didnt do anything for me except drain my wallet another 20 cents. crrllmich is right, no need to run a higher octane unless your engine needs it.

 

carbon build up on pistons own! first it builds up then it creates higher compression and we all know what higher compression means but yea anyways i wouldnt but yea w/e i stay in between the two just because i can

 

I run 91 chevron in my car.when I run anything else it runs like crap,I don't get the throttle response with lower grades of fuel and for some reason I get better mileage with the higher octane.almost 270 a tank around town.

 

I have no genuine textbook statistics for you, but from my experience, depending on where you go, sometimes your better off with 87, sometimes with 93.

7-11, for instance, almost always seems to make my car run ****ty if I put 87 in, so I go 89 if I'm there.

mobil I run 87, never had a problem.

what I also try to do though, is every couple of months I go to shell and plop a nice big tank of that stupid v-power 93 in my car, and run with that for all 5 days or so my tank lasts.

I hate to say it, but that stupid v-power seems like it makes a difference.

it sure as hell beats the $2.73 "fuel injector cleaner" that has not once ever made a difference on my car.

in fact, the only "injector cleaner" that's ever worked for me was this stuff at one of the local lube places around town where they somehow(I never have really figured this out) directly connected some sort of pressurized tube to the fuel injectors and ran the car, as well as pouring another bottle directly into the throttle body itself. the car ran really really bad for about 4 minutes, blowing out all kinds of carbon, but when they were done, I drove off like a bat out of hell(something up until that point I couldn't have done on the car, regardless of octane) and for the first time, saw my injectors SPRAYING instead of dripping onto the throttle plates.

so, run 87, if you're having fuel problems, throw in shell 93 octane, if you're still having problems, look for something like that.
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sorry for the babbling on thing guys, I have a tendency to drift off to similar but different topics, heh.

 

i always ran amaco 87 never had a problem then they left colorado, i went to conoco and the car ran like s, even the 91 it wouldnt get out of its own way, the shell vpower i ran before i tore it down and it seemed to like it, there is a place out here that sells 93 talking about putting a 96 pump in adn it contains alot less ethanol, our gas out here is loaded with it.........

I think part of the problem is people like my mother and sister and brother and girl and well you get my point run 7-11 today, shell the next time, than conoco, then safeway, me and my dad always ran amaco 87 everyfill up with a lil marvel mystery oil in the tank and neither of us have ever had any issues with nasty buildups or breaking down or anything..find one and use it every fill up

 

i just put in a bottle of that berrymen's chem 12 to see how it works.so far so good.

 

if your motor is stock save your self the money at the pump use 87 only higher octane fuels for higher compression motors , regular fuel for regular compression plus 87 is slightly better fuel econo than higher octane

 

damn you break 200 miles on a single tank no way man i run from full to empty with only 150 every week. i wish i could hit 200's but then again i do lots of vroom vroom

 

Well I guess I learned something new, thanks guys. I have never in my life pumped anything under 93 in it, so next time i fill it up im going to pump 87 and see how it does.

 

give it a shot! i doubt you will notice a difference!
kent

 

There is one negative that may happen when running a high octane fuel. The '8746 ECM does a forced knock test. It actually tries to make the engine knock by cranking in timing. If the test fails timing is pulled (engine becomes a dog), and a code 43 is set.

The test is run during the first and sometimes second (if the first attempt fails) WOT modes. On occasion with a high(er) octane fuel this test may fail. If so, then a lower octane fuel would be better.

If the test passes, then no problem.

RBob.