Question
 

What is the difference in the 87, 91 , and 93 octane gas. If I run the 93 is that better for my stang? I know it says like it makes your engine run cleaner, is that all BS? what do you guys run on your stangs?

Read about it here:

Octane info at RHC

I read it but i still dont know which is better for my engine 87 octane or 93 octane.

Always use the LOWEST octane you can get away with. IE 87 octane for your 03 vert. If you buy that Cobra, you'll have to run 91 octane, but the engine compression and timing are designed for it. The GT is designed for 87 octane.

Oh i see.... But my dad will be driving it for like teh first few months till i get my license and what if he doesn't believe me abou the 91 and puts in 87? Do you think when we buy it teh dealership will tell us we have to put in 91 so my dad doesnt just think im making it up.

If you buy the cobra, just open the Operators manual and read about the fuel. It will tell you in there that you MUST run 91 octane. Not to mention the knock he'll hear with 87 in it.

You should be able to look at your owners manual for your GT, it will also tell you to run 87 octane.

You know what really tickles my mind now. About a year ago we bought my sister a 97 neon, and she put in regular 87 and it started pinging. Us all being car n00bs though the engine was dead, and when we took it to teh mechanic, he said yes, if you keep running it it will blow. But just thinking about it... maybe it just needed higher ******* octane! I mean ti started up and everything just went ping ping ping... god damit!!!! we spent 2000 on a new engine for nothing.

Also I dont know if used cars come with a manual but is there somewhere on the internet to print out a cobra manual? This is coming from a ford dealership.

LOL, well there are reasons an engine pings when you use 97 octane. Could be carbon build up in the cylinders, poor EGR, etc. All of which are cheaper to repair than a new engine! If a car does knock, put in the next higher octane, if the knock goes away, it's definately detonation (engine knock).

Also I dont know if used cars come with a manual but is there somewhere on the internet to print out a cobra manual? This is coming from a ford dealership.

I'm not aware of any where that has them online. If you buy it from Ford, they should be providing one to you. Make it a condition of sale.

used cars usually come with the manual, but you never know what the previous owners may have done with it. a car that new should have the manual. 95mustanggt he wasnt using 97 octane it was a 1997 neon with 87 octane. we have a 1997 neon too (funny enough) that runs only 87 octane and is perfectly fine. its my sisters car so i could care less and didnt read the manual, but im sure it says to run 87. my mustang says to use 87, but ive only ever put mobile 89 in it. peace of mind i guess. when my dad fills it he uses 87, and i cant stand it. its all in my head im sure.. but i seem to get worse gas mileage for some reason (by the numbers).

It's not in your head, higher octane does give better gas milege.

Did you learn nothing from the octain post you read??