99gtstang08

Just like the title says, I have a 99 GT and I like to put premium in it. Will this actually hurt the performance because the computer is set up for a lower octane? I use premium because I feel like it burns cleaner and prevents knocking. This maybe a dumb question but it never hurts to ask.

99 GT vert

Yes you can but you are just wasting 20 cents a gallon

99BlackPonyGT

yes you can run it, but you are wasting money....it doesnt burn cleaner (atleast i havent heard this..i could be wrong?), and it only prevents knocking if you have your timing bumped...for a stock tune, you should be running 87, your not going to have any detonation

99gtstang08

Ok thanks, I will def. go back to using 87. What company do you guys think has the best fuel? I have heard that BP has the highest oxygen in it, clearly you know why that is good for a combustion engine. I wonder if that was just made up or is it really true?

99gtstang08

Also, I forgot to add. When I turn my A/C on the car just doesnt run right. It feels like the power is cutting in and out at weird intervals. I know there will be a difference when running with it on but this just doesnt seem like it should be happening. Any of you experience this same problem? What can I do to stop it?

loweredfourpointsix

this will solve your problem with the ac

http://www.poweredbyford.com/store/i...3024c187291efa

ac robs power

99gtstang08

I would do that except it is still my DD so I still need the A/C sometimes when the windows arent cutting it.

99BlackPonyGT

fuel: run whatever you want...but make sure to try and run that same brand consistently...they all have additives, so sticking with the same brand doesnt mix them all up in your car

for the a/c...try to clean your IAC valve... my IAC was so bad if i was idling and i flipped the ac on and off rapidly 5 times the car would actually stall out

nos-nick

hey I new to the forum and I should say whats up. Hears my opinnion, have you checked the diff. in mileage from 87 to 93. The 93 you will get better mileage than 87. and your engine will be cleaner. (not as much carbon build up) i get 230-240 miles a tank on 93 and 190-200 from 87 give it a try

mustangman03

Sorry dude but you are wrong i have had a car i ran both 87, 89 ,and 93 and i got the same fuel economy. the fuel doesnt burn any cleaner either that is in the quality of gas not the octane rating. the octane rating is how slow the gas burns in the cylinder, 87 burns faster than 93. So there is no benifit from running 93 over 87 unless you have a tune for 93, Forced Induction, or higher compression. Now as far as which brand of gas to use i dont know but i like trying to find somewhere that doesnt have the 10% ethonal because it doesnt get the fuel economy as straight gas.