To add one more reply that may make it a bit more clear.
Consider that the higher octane fuels (slower burn time) will be detected by the PCM and alter the running program enough to cause some effects however small that are not in the best interest of the engine and it's running, over a longer period of time.
Believe it!, there is much more going on in these systems than you understand.
The computer is self learning and can shift it's operations over about a +/- 10 % range that does not alway result in the best running.

 

I use 120 octane fuel...NOT FLUE...and my truck does the 1/4 mile in 10 seconds. When I use 93 octane I loose a good 4 seconds with the same run

Wonder what will happen with JET fuel

Seriously...87 octane is all thats required for effiecient operation of a "stock" tuned truck.

 

Saving money is not the point. If you read my initial post, I said that I can get premium gas for the same price as regular, and regular here is 89 octane I believe. I was just wondering if it would be better for my engine, in the long run, to use premium (93 octane) over regular. I just want what's best for my truck in the long run not stir up a hornets' nest here by asking a simple question. I used the search function and didn't turn up much of the exact information that I was looking for lees99f150 , so I started a new thread--that's why I joined the forum--to learn more about my new investment without being called an idiot. I am a noob to this forum, but not at all a noob to forums and how they operate. My master's is not in combustion engine science, that is why I am here.

 

I doubt your going to hurt your truck, I also beleave your truck will run better, I have ran a few tanks of 92 octane threw my truck on ocassion and I notice better mileage and my truck has more get up and go...oil companies have you convinced that 87 octane is the way to go, maybe it cost's less to refine, so they can sell more of it, cause you use more of it.......to offset any gain in using a a higher octane, they up the price....ask your Ford dealer if running 93 octane will viod your warenty, I'm positive they want you to use 87-89 so they can clean out your flue sytem, clogged injecters at 60,000 miles when your truck is off warenty.....

 

octane has a burn rating... if your truck is tuned for 87 then a higher octane will not gain u a thing... it wont hurt anything either.. same spark timing, same amount of gas in cyl. same compression. a tune will advance timing and tell ur truck it is ok to burn at a certain oint because you have the right octane and will not hurt the engine if it does. so a tune for 87 and u use 91 wont matter.... now say if ur tuned for 91 and u use 87... the spark will be too soon for the 87 fuel which will damage ur engine. its all about the tuning. octane in gas is octane... but some will burn fast n evenly more then others! so benifet without a tune

 

Check out this quote from Mike Troyer

 

Like already has been mentioned. Higher Octane fuel provides no added benefit unless your truck is tuned for it. If you can sometimes get premium gas for the same prices as 87, then why not buy a tuner and during those times run program for premium gas so you can take full advantage of it?

cyclone vampire, I haven't heard many oil companies pushing their lower grade fuels. I know Shell is always promoting their Shell V-Power fuel that is suppose to keep your engine cleaner than other fuels. It's also suppose to be 94 Octane but the pumps still say 93. At least the Shell rep I gave a Ride from NPR back to New Orleans told me it was 94.

Here's an explantion on the 'octane rating' though

The Octane rating has become a rating in how the fuel will resist auto-iginition from heat remaining in the cylinder as well as the compression of the air/fuel misture. n-heptane and Octane (2,2,4-Trimethylpentane, also know as isooctane) have been marked as the two standards on the scale. n-heptane recieves a 0 on the scale and isooctane is the 100 mark. Some things like Xylene and Toluene (Both are actually Benzene rings. 6 carbons that form a circle.) have higher 'octane' ratings than isooctane which is why you can get fuel that's like 104 or higher octane rating. Can also raise the 'Octane' of your fuel by mixing in Toluene or Xylene.

There is a lot of left over heat in the cylinder that can cause the fuel to detonate before the piston reaches the top and starts on it's way back down. Severe detonation can actually cause the fuel to ignite before the piston has passed TDC and cause it to actually push the wrong way

 

all i can say is omg i never read such bull in my life. 87 will run the best in your truck. it is just as clean and has the same additives to keep your engine clean. even if it is the same price go with the 87. The higher octain doesnt run cooler (lol) is just takes more heat and compression before it pre ignites. And yes after it ignites it burnes the same as 87. You would only make more power if your timming was advanced or you were running a supercharger or high compression. You vehicle does learn alot but never goes over the timming curves programmed in your puter. the only thing it would do is retard timming incase you had crappy fuel and it started to detonate. SOOOO use the 87 or the 93 the difference if at all would be hardly noticable with your truck.

 

I rest my case.....But its your $$$$$..

 

I agree with Intel486. If you can get 93 for the same price as 87, then buy a tuner to take advantage of it.

If your engine is not tuned for 93 (which it is not when stock), then there is no use running it, and as was said in the quote from Mike Troyer, can possibly hurt performance.

So add this as one more vote for "Run 87 unless you get a tuner"

 

Yup - add this one to my growing list of BS, Urban Legends, and Old Wive's tales ;-))

BS: FlowMaster is a performance muffler
BS: Don't swim right after eating
BS: Chebby makes good trucks too
BS: You can't burn on a cloudy day
BS: All gas is the same quality
BS: The Atkins diet
BS: Lightning never strikes the same place twice
BS: Premium is cleaner the Regular
BS: Coors is better than Miller
BS: You don't need gears on a lifted truck
BS: You don't need a brake upgrade for larger wheels
BS: You don't need a tranny cooler
BS: Guns kill (it's the nut behind the trigger)
BS: Cell phones kill (it's the nut behind the wheel)
BS: You can run your plugs for 100K miles
BS: You don't need to change your front O2's often
BS: You don't need to replace your fuel filter often
BS: Spark plug blow-out is not caused by improper install torquing
BS: You should run Premium instead of Regular in a stock truck

Cheers!
Vic

 

I just went through this with my friends mustang. If you run premium and the truck or car is tune for 87 your wasting your money and in the long run you will make more carbon in your engine faster b/c of the unburned fuel. If you want to run premium advance your timing to accept the slower burning premium fuel. You will gain a few hp and get better gas mileage but you have to run premium or your will risk engine knock.

 

Wrong! If your engine is tuned for 87 you will not magically get more power by using 92. Energy to move the piston remains the same, it is dictated by the friction in the engine not the octane of the fuel. Some engine controls can advance or retard timing to compensate for different fuels but it is a narrow range.

 

Octane has nothing to do with cleaning ability. In some cases running higher octane fuel then you are tuned for can actually increase carbon deposits.

 

Right on, Norm;

In fact, MT once indicated that the '04+ F150 platform had a much better spark advance / knock sensor system than the '03 and previous years, that allowed better utilization of premium fuels over and above the current octane requirements the tuning was done for - e.g; if you were running a 92 octane fuel AND tune, then put in some 94, the system would allow more advance to effectively utilize it.

Cheers
Vic