93 octane on a 87?

[jimmyzgarage]

From my understanding, the F22's can't really take advantage of high octane unless you've advanced the ignition. Some of you guys have said that you can tell the difference, ie. your engine runs better. While some may think it's in their heads, quite literally it could be carbon buildup in the head, which will cause your compression ratio to increase a little. Thus requiring a higher octane gas.

Newer cars like my Ford Expedition, have knock sensors that will advance the ignition until it knocks...higher octane fuel makes a big difference on my butt dyno and in my wallet.

[trendyexr]

No one really answered my question :P. In my manual (1990 ex) it says that the car requires premium fuel (91 octane) to perform properly. So, maybe i'm crazy, but the car technically is supposed to run on premium.

Aaron

[xplode]

in the manual for my 96.. it says Running on a 86 octane or higher... higher means that it can take 93 for one tank? i just want to run thru some of that gas that has the new cleaning stuff in it.. cus in my manual it says using gas with cleaning agents to prevent build up is good.. so i think i might do that one tank full.

[accordztech]

blah that cleaning stuff is co. but if u have a 86 or higher avalibility...which is 87 and u run 91....then the cleaning crap inside is basically a waste cause its not cleaning as much as it should

just go to the store and buy some lucaus fuel injectrion cleaning stuff and you will be safe. it has more cleanability and cheaper than what the gas stations have to offer.

trendyexr: oddly urs says premium so i guess that what it needs...what engine modle u have...like f22a?

[xplode]

yeah but i dont trust putting anytyhing into the engine anymore... everything you put in affects the engine... which is why i wont use seafoam on this car.. i dunno.. atleast gasoline is made for all cars.. where cleaning agents honda doesnt reccomend lot ofthe aftermarket cleaning crap.

[accordztech]

well you do have a point but listen to this.

in normal gas with its 1% of concentrate for additives...carbon builds up in ur tank. yes it is clean but it doesnt have enough power to clean everything in the syetem.

its true that some cleaners are really harmfull in engine, or more potent. stuff like stp cleaner using every gas fill is a waste and realyl is bad.

the only good things that has been tested is

chevron cleaner
lucaus
and some others

these were put into a styraphone cup which degrades when harsh chemicals are put into it...the cup will represent the seals...and they passed the test

now this is fuel additives and what it does to your gasoline.



as u can see no fuel additive, even with the nromal fuel is toast.

this test was done by adding the correct mixture of gas and fuel additive in the car. then it was heated just as it was heated in the cycle of combustion with the cylinders and the spark plugs.

and this is the results.

http://bobistheoilguy.com/videos.html

there is a couple of other tests on that page as well for fuel injection cleaners.

these guys on this site are pretty smart, the dude who does these tests is a chemist...pretty smart one too till he had a stroke a year ago and hasnt been back since.

so there are good additives and badd additives...really i stick with what i know is good....

as far as seafoam. it is only bad when u use it badly. spraying it into the intake manifold system actually helps by cleaning shit that u cant see or get to. then when it gets down to the pistons it cleans the top of them and if left when the car is off it seeps past the rings a bit to clean there as well.

helping ur combustion system at the same time. its not wrong to use these...just got to use it wisely. no pouring of fluids, always find a can that sprays....and let it go into the car at a higher idle...so that ur car wont suffer. trust me its fine. ur doing less harm than good.

have u ever seen an engine that didnt use any additives (intake manifold wise)? oh gosh there is soo much black shit on top of the pistons...fuel injectors and stuff.

i tuned up alot of cars that have this problem...there is just too much shit int here.

now with the oil additives..i say stay away from...those are the stuff that will harm ur engine, if they dont harm they create clotts which i dont like.

there is one certain product that has been tested for the oil which some dont agree on but i seen it work on www.bobistheoilguy.com site and my car. www.auto-rx.com

really u just have to look at the contents, solubility, acidic and everything...thats what this site is for it helps u.

[xplode]

Even so.. im wondering if honda carrys like a OEM like throttle spray type stuff that is made for the hondas so that way its 100% safe.

[accordztech]

hodna does use things, but see what they do is they purchase whats on the market. usually for their fuel injection s hit they use some pretty potent stuff...but no matter how harsh it is it gets the job done and a oil change is needed.

amsoil power foam is good.

go past ur doubts..there is nothing safe...even gas has its disadvantages.

but as long as u use it it will be fine.

[xplode]

yeah but im gonna maybe see if they can spray some cleaner in the throttle next time i get a oil change.. just to remove some junk.. But yeah i decided im going to run a tank of 93 V-Power thru my tank because i was talking to fizz and he said it will not cause any downsides.. no unburt fuel or any of that junk.. but yeah... Ztech what you thinks best? cus i want somthing safe.. i dont want anything thats going to cause my car to get all funky from the inside.

[FishyMan]

edit..

well, i am curious as how the ecu works in correlations to the octane rating suggested in the manual.

so an ECU is programmed just for 87, and you put 87 right? great no pinging ..
but if u put 85, then the knock sensor kicks in,
but if u put 92, then what happens, is that a waste of money then? does the ECU know how to work w/ the 92?

or does it work like this, if u put 87 and it pings, and when u try 89 it doesn't ping, thus ur engine needs to be serviced because the 87 octane which was recommended cause the engine to ping. but i guess how does the ECU work, is it programmed for just one octane rating or does it know a range of octane?

does anyone have credible source or articles regarding the ecu, knock sensor in relations to the octane ratings.


thanks

[xplode]

?? whatt... dude after reading that i kinda laughed because i have no idea what you were talking about and why you kept saying technical lol. .. can you explain it better for meh?

[FishyMan]

my fault .<- noobs.

well i edited..

[Tenji]

Just reset the ECU by taking the negative battery cable off if u plan to switch octane rating.

[xplode]

now i understand.. The ECU is not have any effect on the octane of the car.. the pistons do.. Its the pistons compression that combusts the fuel.. ECU has nothing to do with it.

[Cactus]

Octane rating

My 92 LX is specified for 86 octane, so either the EX needs a little more stable fuel or for some reason the earlier cb7's were rated for higher octane fuel.

As far as octane rating, the higher the octane number the more stable (higher combustion temp) the fuel. That is why higher compression engines need a higher octane fuel. There is a direct relationship between pressure and temperarute. Thus, as the engine compresses the fuel the temperature of the fuel goes up. The higher the compression ratio the more the fuel is compressed and thus the higher the temperature of the fuel in the chamber. If you are using a fuel with too low of an octane rating the fuel will actually begin to combust simply because it has reached the temperature at which the fuel will self-combust. This is 'knocking' and is very hard on an engine. Combustion initiated by the spark plug results in a flame front that travels across the combustion chamber in an orderly manner. Not only does 'knock' combustion have a very random flame front (not what the engine or the chamber is designed for) it also combusts before the piston is in the proper location for combustion causing more stress on the engine.

I have not personally tried 91 or higher octane in my LX, but I might next time just to do it. I don't believe there should be any difference at all, however.