What type of gas should i run on my stock NA 89 90 91 what octaine? and when i start to mod it out what octaine should i use? and what octaine for turbos? also i forgot to add fuel perservative to my car and there is like a quater of a tank what should i do?

 

Why do you want to put fuel preservative in your tank? Is the car going to sit for awhile? Run the lowest octane you can find for your n/a. The high octane stuff will do nothing for you except empty your pockets. Only use 91 octane if youve got a turbo.

 

87 for n/a, 89 for turbo (imo)

 

well it has been sitting and i need to get out of the garage and i forgot to put fuel presurvatives in it what should i do??

 

Stock just run 87 (or the lowest you can find) octane. Higher octane just helps prevent detonation, nothing else. Once you start modding I guess it depends on what you've done. If the gas is that old pull the tank and drain it.

 

Or use the drain plug.