As soon as possible, but as stated before, octane boosters only slightly raise the octane, I'd still baby the car while you're on bad gas.

 

hmm, i was thinking about fuel injector cleaners w/ the octane boosters. Gets rid of residue/corrosion etc. But ill do it before my 1K mark. From damn 35mi on monday to 7xx today :X

 

A lot of those cleaners work by just raising the octane so the engine burns hotter. When it burns hotter things get cleaned. I've used the Chevron Techron additives on cars before without problem, but there are some people who say they can be harmful.

Honestly, if you drive your car hard then chances are your head is super clean. I knew a guy who had 220k on a VR6 Jetta motor. It was an NA beast that ran low 13s. Even at 220k miles with the stock head the head was super clean. He did have to replace the block though. He drove the **** out of that thing.

 

ehhhh, wait till you get about 25,000-50,000 miles and clean it with seafoam.

 

Of course.

I have pulled the car in front of a pump only to find that the 91 octane gas is out or broken. So I put about $20 worth of 87 in the tank. The car ran fine. Of course the next time I put 91 gas in the car.

 

i got pwnt. Guy put 89 at the gas station by accident when i asked for 93 and my gas mileage went from 23 to 13. It made a big difference. The car is obviously running rich now for saftey because I blow black smoke (fuel) at like 3/4ths or WOT. I used up half and put in 94 =\ It should get better

 

My Dad took the Z out for a spin, I had 1/2 a tank when he left. He came back and it was full (how kind), except he put in 87. The dealer probably filled it with the same. But my Z is fine.

 

Octane has nothing to do with how "hot" the gas burns. 87 octane burns at about the same temp as 91 octane. Octane just determines how fast the gas burns. Low octane gas burns faster and ignites easier because it actually contains more energy than 91 octane gas. This is why low octane gas can cause knock (aka pre-ignition). The addatives in gas clean your motor because they are actually detergents. The reason why some people think higher octane gas cleans your engine better comes from the fact that gas companies used to put better detergents in premium gas. Now, they pretty much use the same detergents in all grades of gas.

 

the lower the flashpoint, the hotter it will be. So a high-octane fuel would theoretically be hotter?

 

All you need to know about octane levels is that higher octane means you can run higher compression and more advanced spark timing before it spontaneously detonates from the heat of compression (knock/ping)

 

In a high compression engine it WILL burn hotter. During compression, lower octane mixtures will detonate earlier (pre-detonation a.k.a knock). By doing so, they're not reaching maximum compression before detonation. Contrarily, higher octane gases will reach full compression and provide a more powerful ignition which is also hotter.

 

In your example (high compression motor), your problem is now detonation, not which fuel cleans the engine better. My reply was meant to say that in an engine that can safely burn both 87 and 91, 91 will not clean the engine by burning hotter.

 

Yes you're right. However, my original statement is that the cleaners raise octane to burn hotter. They do this by introducing other chemicals, similar to alcohol which does in turn raise octane and burn hotter, but it's not because of the octane raising that they burn hotter, it's because of the chemicals.

However, when I wrote that, I wrote it with the Z in mind. Dynos and just common sense shows that 87 in a Z is not optimal and does not reach maximum compression because the timing is altered to ignite it before full compression (to avoid pre-det).

Octane boosters and fuel system cleaners work in similar ways by raising the octane. They pretty much all use Methyl cyclopentadienyl manganese tricarbonyl (MMT) and/or ferosene. MMT is more popular though. It raises the octane and runs hotter.

Standard higher octane gas doesn't add additional ingredients, it just reduces some of the impurities in the gas because it's refined better. In a normal low compression engine, the lack of impurities doesn't change the burn temp.

Sorry for the confusion.

 

Not true, Calorific value or the energy content (specific energy) is the same for all octane levels. Around 2.92 MJ/kg. The only difference is the how easily it ignites.

 

Fuel system cleaners work by dissolving deposits, not burning them off. Your injectors never get hot enough to burn off deposits.

 

I was told by a chemical engineer at Chevron that 89 and 91 octane doesnt really make a difference, i think he said 93 and above is where the diference is

 

my stupid brother put about a gallon of 87 before i caught him. but 87 actually is not gonna hurt u.. just dont use it all the time

 

This is EXACTLY WHY I pump my OWN gas...Although it is EXTREMELY annoying to have to tell the towelheads 3 or 4 times in a row that "I'll pump it myself".

Summabytches are like Robots programmed ONLY to pump gas...and when you tell them NOT to...They have this "Does NOT compute" look on their face and get confused....

 

[QUOTE=i8acobra]Octane has nothing to do with how "hot" the gas burns.QUOTE]

Sorry to bust your bubble but the higher the octane the hotter it burns, thats why the same warning goes out for people running higher octane than they should be risking burning a hole in their motor.

 

wow.... just wow...