What kind of gas do you use?
#29
RE: What kind of gas do you use?
I feel like there is a lot of mis-information here...
First off... like stated before 100 Octane is not anything like a Nitrous setup. NO is like forced induction. gas is still just gas, regaurdless of octane level.
Increased octane reduces the temperature at which gasoline will ignite w/o a spark (temperature and pressure cause it). When running higher compressions, you need to run a higher octane level to prevent the gasoline from ignighting before the spark plug fires. If you have pre-ignition, it can be deadly for your car. This is heard w. a noticable ping sound, also known as knocking. If your motor is knocking, stop driving it. Increasing octane levels will prevent knocking. However, if you do not need a higher octane level, you're just wasting your money. If the manufacture recomends 91 octane, put in 91 octane to your stock motor. if you increased boost, or any other performance mod's, and you experiance knocking w/ your current gasoline, increase the octane. This is why when you chip your car, they recomend various octane levels. Octane does not increase performance, it allows performance increases. off the top of my head, the only car i know of that will allow an increase of boost based directly on the computer learning what octane you are running are the old sweedish saab turbos. The ECU could be manually adjusted to vary the knock sensor, thus you could change the boost rate/knock sensor level, etc. It would allow boost to climb until the knock sensor kicked in. Putting 100 octane or octane booster in to 91 in a stock motor will do only one thing. put a dent in you rwallet.
First off... like stated before 100 Octane is not anything like a Nitrous setup. NO is like forced induction. gas is still just gas, regaurdless of octane level.
Increased octane reduces the temperature at which gasoline will ignite w/o a spark (temperature and pressure cause it). When running higher compressions, you need to run a higher octane level to prevent the gasoline from ignighting before the spark plug fires. If you have pre-ignition, it can be deadly for your car. This is heard w. a noticable ping sound, also known as knocking. If your motor is knocking, stop driving it. Increasing octane levels will prevent knocking. However, if you do not need a higher octane level, you're just wasting your money. If the manufacture recomends 91 octane, put in 91 octane to your stock motor. if you increased boost, or any other performance mod's, and you experiance knocking w/ your current gasoline, increase the octane. This is why when you chip your car, they recomend various octane levels. Octane does not increase performance, it allows performance increases. off the top of my head, the only car i know of that will allow an increase of boost based directly on the computer learning what octane you are running are the old sweedish saab turbos. The ECU could be manually adjusted to vary the knock sensor, thus you could change the boost rate/knock sensor level, etc. It would allow boost to climb until the knock sensor kicked in. Putting 100 octane or octane booster in to 91 in a stock motor will do only one thing. put a dent in you rwallet.
#30
RE: What kind of gas do you use?
The higher the Octane, the cleaner the gas is as well, which is why some people choose to put 100 Octane into their car once a year to help clean the crap out of the engine from crappy gas.
I have noticed on my A4 since switching from 91 to 94 over 5 tanks of gas now with no other mods that I am getting better gas milage and my car idles better. If there is a logical reason for it or not, the car likes the 94 better even though my chip is rated for 91.
I will see if 91 versus 94 makes a difference on my next tank. I am doing 21PSI @ WOT right now, so if it drops on 91 versus 94 it'll be the gas (with all other variables constant).
I have noticed on my A4 since switching from 91 to 94 over 5 tanks of gas now with no other mods that I am getting better gas milage and my car idles better. If there is a logical reason for it or not, the car likes the 94 better even though my chip is rated for 91.
I will see if 91 versus 94 makes a difference on my next tank. I am doing 21PSI @ WOT right now, so if it drops on 91 versus 94 it'll be the gas (with all other variables constant).