Regular or Premium

[Big Red Monster]

i do the exact same thing you do time the lights use cruise control and easy take offs, well I need to use prolly a little more on take offs because getting this big mud terrains to move is a little harder to do. Im getting like 11 miles a gallon right now because i finally reset the mpg average gauge to accomodate for my intake and exhaust, I need a tuner and a jet mass air flow sensor to maximize those mods, i think Im gonna go with the edge actually i saw one of ur posts saying you get 15 in the city, I originally thought you had the 4.6 i did not know u were getting that mileage with a 5.4, prolly if you free up your exhaust it will increase the mileage even more. im also considering useing part of ur intake mod with my cold air intake if i can figure out a way to keep my fog lights and do it lol

 

[ChrisJ]

I run regular in the expi as thats what it is tuned for from the factory...I have learned from being in the mustang community if the modular engine is tuned for regular run regular...As you wont take advantage of the extra octane...

I do fill it up once a month with Premium just to knock the carbon off the valves...

 

[Toyman]

baker I swear there are so many idiots that come in my gas station and put 87 in there expos then they whine "these trucks are sh*t they run like crap" one day i told one of them use the 93 next time u come in if the truck isnt running better ill buy your damn gas for you. his truck ran so much better on 93. Im 19 I dont make alot of money but when it comes to fueling up Ill only use 93 or higher Im not gonna cheap out and f**k up my truck to save a dollar

Crappy gas and octane ratings are not synonymous. A higher octane rating doesn't mean the gas is better only slower burning. 87 octane in my 5.4L '08 Expy works great. 94 octane in my KB boosted 5.0L Mustang is essential.

 

[Big Red Monster]

i understand even 93 octane can be sh*t depending on where u get it but still i know if i run my 02 on 89 or 87 it knocks and dosent run as well, if my friend runs his mustang gt on 87 and not premium the cel comes on, same with my dads 97 expy run 87 and the truck really lets you know that its pissed at you, run 93 or higher and its happy

 

[ELVATO]

I run what it's tuned for. Right now, it's 93. Otherwise, it would be 87. I always thought running 93 in a car that isn't tuned for it promoted carbon buildup. This, over time, creates pre-detonations, which ultimately necessitates the use of 93.

I might tell my brother to put 89 in his car for a few tanks and see if he notices a difference. I wonder if the knock sensor would advance timing enough to get some gains out of it.

 

[Toyman]

I might tell my brother to put 89 in his car for a few tanks and see if he notices a difference. I wonder if the knock sensor would advance timing enough to get some gains out of it.

I may be mistaken but I thought the knock sensors only sense knock which results in timing being pulled until the knock disappears. Timing is based on the load vs. rpm map programmed into the tune.

 

[GEORGETOWN]

I usually run 87 but after hearing about the mileage with sunoco 93 with no Ethanol, I think I am going to try the Sunoco 93 and see what happens.

Sux because there is a BP right across the street and the Sunoco is about 2 miles away!

But hey its worth a try!

 

[ELVATO]

I may be mistaken but I thought the knock sensors only sense knock which results in timing being pulled until the knock disappears. Timing is based on the load vs. rpm map programmed into the tune.

Could be. I thought they advanced or retarded timing to be on the verge of knock (all within a set range dictated by the tune.)

Still going to try it and see if there is a difference.

 

[bundy]

50% better mileage running 93 other than the 87 recommended by the factory specs just don't seem right to me????????????

 

[Big Red Monster]

i ran 100 octane on my truck yesterday, man my 5.4 loves that gas its running so smooth and the acceleration is alot quicker