gotboost

Im curious about the statements that the tuner companies make. They say that there tunes are so effecient they will not only make you faster but also give you better fuel economy. I think thats b.s. but i guess now a days u never know. Still plan on getting one, 1day, Just curious

racer02GTstang

well.. more hp means less power needed to get goin... so therefore better mileage... also can lean out alittle bit to get rid of the excess fuel usage.... it just depends.. it wont help if you always on it though.

The Great Cornholio

With respect to the "canned" tunes that come with them, the hype falls short of reality. This is true whether it is DiabloSport or SCT pushing the hype. They are a very good means, however, of getting a dyno or custom tune developed for your vehicle; they will do all the same things a chip can do and more.

ibeeskeef

You get better gas mileage because you have to run higher (93) octane. It is more expensive to buy but gives a little cleaner burn so you get better mileage. Pretty even trade in my experience with price vs performance over 87. Tuners are necessary for new gear ratios and turning off the stupid traction control. After that, get a custom tune and use it for the custom.

sandcracker21

i am goin to havta agree, a tuner is a very key thing to have for your stang,

there is SOOO much you can do with it, and if you ever plan on gettin gears, you will

need to retune

Car_Ramrod

i heard that, on a stock car like a mustang that has an engine designed to run on 87 octane that filling her with 93 is just more or less a total waste of money. if you start adding some bolt ons or nitrous or a custom tune...then granted you need 93...but i think 87 is just great for stock.

SilverGTV8

Ah crap another missed concieveied octane converstation........

I'll make it short and sweet......

93 doesn't burn any cleaner then 87. The octane rating is a number to identify the potential of the gas igniting prematurlly (before spark, often call detonation) OR lighting in various spots during the spark (not at the spark, often called pinging). The lower the number the easier it will pre-det or ping, as well as, igninte.

93 octane is acutally difficult to burn to ignite (takes more energy) but is stable in leaner conditions and high compression ratios.

Stock 2v 4.6 mustangs can run 87 octane, and is suggested in the owner's manual, BUT not all 2v in stock form can run 87, mine and Dan04Cobra can testify to it. I have run 91 or better since my first tank of gas went bye bye. I tried 87 later on and it pinged BAD, I step up to 89 and the car had a weird flat spot in the middle of the RPM band. I put in 91 and the car is fine. I now have a tune that requires 91 or better, but in stock form I needed it to begin with.

Summary:

Higher ocatne = harder to burn, but better for lean and/or high compression apps. It doesn't burn cleaner, it doesn't increase HP. It is just more stable.

Custom tunes take advantage of this stability with bumped timing and leaner A/F to pull the HP, but even with a good tune you can ping and pre-det on custom tunes. Last summer i had to pull timing for few weeks because of the high temps causing the car to pinging (as an example)

sandcracker21

^^exactly

good post, there are a ton of people on this site that dont

understand this concept

redass02gt

if your 4.6 2v is stock and cannot run 87 octane, something is up.

SilverGTV8

Nope nothing is up. Fact of life. 87 here is not 87 there. They put a lot of crap in the winter gas in the northeast that can cause issues. I trie dthe 87 and it was a no go. Car dynoed strong stock at 224 with only 3000 on the gauge, barly broke in