I have a question about octane & a problem I've been having with my car.. it's a 02 GT with 15,000mi. Sometimes when I start it.. it'll crank but won't start, could it be cause I'm not using a higher octane? I've been using 89 since I bought it.. plus, are fuel injector cleaners good?

 

There was a previous thread about both of these topics but to answer your question... It seem that all mustangs have a problem starting every so often (nothing to worry about). The higher the octane level... the harder it is to ignite so it might be a small contributing factor to not starting right away... Ford recomends 87 for GTs. Fuel injector cleaners are not a bad idea every so often, maybe once every oil change but with only 15k miles it shouldn't be your injectors. Make sure you're turning your key all the way forward and also don't crank for to long just let off and try again. Don't worry about it to much unless it won't start PERIOD

 

Well, I have an '03 GT I have been running atleast 91 in it since I bought it. When i switched back to 89 with the rising gas prices the car acted super funny. The car would run great and then sometimes under hard acceleration it would hit a flat spot mid RPM range, like the car was pulling timing. Plus my gas mileage droped from 22 to 20. I tried 2 tanks, man did I hate it. Put back the 93, she ran sweet, no flat spot and the mileage back up.

Everyonce an a while it takes a bit to lite off, but is not to bad. usually it when it starts hard, I happen to let the ingition go and it will truck its way to starting, makes an interesting burbuling noise

 

Anything but 91+ doesn't belong in a high performance V8. The car is not configured to be economical.

 

Octane has nothing to do with how much hp a car makes, its only purpose is to prevent pre-ignition in cars with higher compression. If your mustang does not have increased compressio, - through either increased compression ratio or increased ignition timing - then you don't need more than what the manufacturer recommends. If you do, then you have a problem.

 

were any of you using shell cause they have been selling bad gas for a few months and they said it was only the regular and plus that was effected. premium wasnt effected. oh yeahh MD how come C&L told me to run at least 92 in my car with the new maf to prevent possable detonation?

 

shell had bad gas? lol.. that's all I've been using for bout a year! but I've had my car for almost 2 yrs & so used other stations before. Maybe I should stick to Chevron? gee, what is a girl to do?? lol

 

About 200 gas stations in the country had bad gas, everything is fixed now too.

As for your MAF, upgrading it requires higher octane. You will have pinging unless you do.

 

so i read the thread about how not to buy shell gas because its bad. so what to i did do yesterday, bought some gas from shell and i am paying for it now. my car is running like ***. i've always had a slight hessitation around 2k rmps, now its all over the place. i drove my car all over the place to use the gas up. my tuner said everything should be ok, and to go fill up with whatever i use to use to override the bad fuel. she's coming back to me slowly... i am pissed because i had to try it for myself and sure enough... thanks for the heads up though... i should have listened.

 

hey im sorry about that im never using shell anymore. they said premium wasnt effected but i guess it was. like i told you that my car just didnt seem to be running up to par. my car is brand new and im just learning to feal for stuff in the car and i just had a bad fealing about rough idle and something just didnt seem right. i put sunoco in the other day thats one brand diablosport recomends using when using there stuff also. and it seems to be running better. hopefully i can flush out all the bad stuff. hey what about fuel sytem cleaners are they ok for this car. i mean if there is any crap left over in my tank or on my injectors i want it off. i used to run fuel sytem cleaner on my formula but are they ok for the stang . thanks and sorry about your car i hope both of are cars get better soon.