Will 93 octane help in passing the emission test ?
chen.t.wang
a much better understanding of pre-ignition and detonation. However, I still
have one more question :). It seems to me, if a car has been tuned for regular
gas (87 octane) - that is, ignition occurs at the best moment and yields
the most torque, then switching to a higher octane will cause combustion
incompleteness, thus, giving higher readings of CO and/or CH. Is this right ?
I know quite a few people claimed using the 93 octane after tuneup helped cars
that would otherwise failed the emission test. Is this just psychological or
is there certain truth in this ?
I'd appreciate if someone can shade some lights on this.
Chen Wang
Michael Bradley
>I know quite a few people claimed using the 93 octane after tuneup helped cars
>that would otherwise failed the emission test. Is this just psychological or
>is there certain truth in this ?
Cant answer this one but I have heard stories about putting a couple
of pints of alcohol in the tank and then passing the emissions test.
Anyone else heard of this?
Michael Bradley
Don Eilenberger
I can pass along a first-hand story about adding alcohol to the gas..
in this case methanol... back many years ago when New Jersey just
started doing emissions testing, a friend, who had heard adding a
few pints of methanol would help him pass emissions (he'd flunked)..
figured a gallon would help even more. He added this to an almost
empty tank and happily went to the inspection station. He flunked..
not for excessive emissions, but for NO emissions! (The sensors
were perhaps somewhat more primative in those days).. He said,
and I quote, the inspector said "I know you did something.. I
don't know what, but I KNOW you did something..".
I wouldn't recommend it as a regular diet for your car, since it
is a given that methanol WILL eat up rubber hoses and seals in
your fuel system.
Don Eilenberger
sl...@cc.usu.edu
of itself, but I do know that if you get about half a tank of gas (8 or 9 gal)
and add a gallon of alcohol, and drive around for awhile to mix the fuel, and
get the engine at operating temp., then you should pass with flying colors,
as long as the engine is tuned respectably. after you do the emissions test,
fill the tank the rest of the way full, unless you want to *really* hot rod
around town(although I wouldn't recommend this if you don't have a good
cooling system)
good luck!
Pete
>
> Michael Bradley
Daniel J Naze
Can you be more specific? What kind of alcohol? I may need to try this
in the future with my X1/9.
Dan Naze
David Johnson
>>I know quite a few people claimed using the 93 octane after tuneup helped cars
>>that would otherwise failed the emission test. Is this just psychological or
>>is there certain truth in this ?
>Cant answer this one but I have heard stories about putting a couple
>of pints of alcohol in the tank and then passing the emissions test.
>Anyone else heard of this?
I don't know either, but the added alcohol would decrease the fuel
input, thereby leaning out the mixture (alcohol has about half the specific
energy as gasolene). The alcohol also burns much slower and more cleanly
which may decrease emissions at low RPM's, which is where tests are conducted
500-1000 RPM and 2700 RPM.
I've ran alcohol in my 911 but not for emission purposes.
DAVE (joh...@wrs.com)
rgh...@bb1t.monsanto.com
> bra...@mdd.comm.mot.com (Michael Bradley) writes:
>
[stuff deleted]
> I don't know either, but the added alcohol would decrease the fuel
> input, thereby leaning out the mixture (alcohol has about half the specific
> energy as gasolene). The alcohol also burns much slower and more cleanly
> which may decrease emissions at low RPM's, which is where tests are conducted
> 500-1000 RPM and 2700 RPM.
>
> I've ran alcohol in my 911 but not for emission purposes.
>
Ok, so what kind of alcohol do you use?
Rick Hoffman.