Fuse pull highly recommended

[strych9]

Originally Posted by OldJedi

OK thanks, now I understand better. I did not realize that there was constant voltage going through fuses 5 & 20. I thought the fuses would only be active when the ignition was on. I appreciate the information.

[flyjbaker]

A houseful is not going to diminish the octane of the entire tank... In theory, yes...marginally. But not enough to cause the symptoms that the sensors pick up on...ie...detonation.

[joes407]

Originally Posted by Hercules

Great question, I worked at a gas station and always wondered that. I don't see how you don't get a hose full of the previous persons grade of fuel. It's got to be sitting there.

i try an buy my gas at stations with separate hoses for each grade. to me it feels like the fuel shuts off at the handle not at the beginning of the hose so im guessing if you only put in 10 or 15 bucks worth that you could lose some octane points from the regular gas caught in the hose from the last customer.

[strych9]

Originally Posted by joes407

i try an buy my gas at stations with separate hoses for each grade. to me it feels like the fuel shuts off at the handle not at the beginning of the hose so im guessing if you only put in 10 or 15 bucks worth that you could lose some octane points from the regular gas caught in the hose from the last customer.

If you put in at least 5 gallons, the amount in the hose isn't going to dilute it enough to matter.

[joes407]

Originally Posted by strych9

If you put in at least 5 gallons, the amount in the hose isn't going to dilute it enough to matter.

if you dont mind me asking, how did you determine that? its a 1" hose 12 ft long, im sure it holds around half a gallon or so

[2012ZL1]

I am glad I have used 94 from day 1

[SlingShot]

Originally Posted by joes407

what if you buy gas at a station that has 1 hose for all the fuel grades? if the guy before you buys regular do you get a hosefull of regular before your premium?

The Blend Valve

One of the first things that a customer will notice at the pump is the variety of choices offered. In most cases, a dispenser will offer several grades of gas -- sometimes as many as five -- each with a different octane rating. The desired octane rating is usually chosen simply by pushing a button. Does this mean that there are five different underground tanks feeding into that dispenser, each offering a different grade of gas? That's not usually the case. In fact, the dispenser can produce as many grades as it wants from as few as two underground tanks, as long as one tank contains the highest grade of octane available at that station and the other contains the lowest. The grades are blended together at the pump -- not unlike the way you'd blend gin and vermouth to make a martini -- producing a kind of octane ****tail. The precise proportion in which the grades are blended determines the octane of the gas that enters the customer's tank.

This feat of gas pump bartending is performed by something called a blend valve. This valve has inputs consisting of two grades of gasoline, each from different tanks. A single, moveable barrier called a shoe is connected to both in such a way that it can be moved across the inputs with a single motor-driven ratchet. As the ratchet opens one valve, it closes the other valve in precise but opposite proportion. This means that when one valve is, for example, 90 percent open, the other valve is 10 percent open, creating a mixture that consists of 90 percent of one octane and 10 percent of the other. By shifting the ratchet back and forth, the blend valve can produce any octane of gas, ranging from the highest to the lowest grades stored in the tanks -- and all octanes in between.

[hairtrigger]

Originally Posted by 2012ZL1

I am glad I have used 94 from day 1

That Chevron 94 with the dedicated pump, hose and nozzle is the cats ass.

[joes407]

wish we had 94 octane down here. never see higher than 93

[DangerZL1]

I'm glad we have 93 instead of 91. I just wish it wasn't an ethanol blend.

[AKA]

I have been reading about this fuse pull since I bought my Camaro last summer. I never did it thinking there was no evidence to back it up and people are just feeling what they think is a power increase because they read about it on a blog. The everything I read about on the internet is true theory. I finally decided to try it after this thread popped up the other day to see it for myself. Well, It didnt do anything for me in the way of feel it in the seat of your pants HP increase. Maybe my car was never filled up with 87, who knows. My car was driven by my dealership from bowling green ohio to pittsburgh then filled up again by the dealer before delivery. I doubt they put 93 in it for both fill ups.

[jimmy5]

We only have 91 here :(

[firecross91]

Disconnected the batt. tonight. Will see tomorrow what happens. Looking at the dyno sheet from the other weekend I don't see any hp drop thru the run from 2350rpm to 5950. That is where to rev limiter hit. Does have a torque blip at 2700 rpm. No drop just no increase for a couple hundred rpm then steady climb again to max at 4000 rpm.

[Richy_Rich]

nice, this would get the PCM to reestablish a basleine on higher octane pump gas and forget the factory low octance / dealer cheap-o-gas rating.