.....but pouring whatever cleaner down the TB does nothing for the injectors......why not pour a good strong dose in the tank....that way the injectors get cleaned along with everything else.

 

Corn ethanol creates an energy deficit and poorer gas mileage, it isn't just "accepted" it is proven. If you want the proof get it from edmunds:
http://www.edmunds.com/advice/altern...3/article.html

 

Just to state that on the valve cover we have two vacuum lines that run into the intake. the 4.0 manifold is the main induction that supplies vacuum ect. So wouldn't you haft to get rid of the waste upstream to deal with the main problem? but do agree with a good injector cleaner along with the intake treatment don't get me wrong.

 

What is there to treat in the intake manifold? It's a dry manifold, only air flows thru it. The last 1" or less of the intake runner (at the head) is where fuel is injected. Again, pouring whatever into the TB or sucking whatever thru a vacuum line won't clean the injectors.

 

It's widely agreed that using premium in a car designed and tuned for regular will not net you any kind of performance gain or MPG increase. Although, and saying purely on a subjective standpoint of my results from putting it in my Jeep. It did make a noticeable difference in the smoothness of the engine, the valvetrain noise and have yet to measure any MPG increase. I can only wager that being an older engine, with less electronics to interfere, the hotter, more efficient burning premium does actually have a positive effect in terms of the engine running more efficiently.

I'm going to run a few tanks of premium (92 or 93 here) through. Then run a few tanks of regular and see if there is a noticeable difference in MPG since that's about all I can actually measure. Valvetrain noise is something I can only measure with my ear so it's hard to convey that into data. "butt dyno" as I like to call it too, basically if the car feels more powerful and more responsive, even a real dyno may not pick up on those changes.

 

Among other things, I'm puzzled as to how premium can quiet the valve train. The only part of the valve train that comes in contact with fuel is the head of the intake valve, not the entire valve train.

 

My F 150 is fairly new, and the reason I get better mileage using the 93 octane is because the premium here has no ETHANOL in it, it is all gas.
Gas has more btus than ETHANOL.
If I could get all gas regular I would probably get just as good mileage with regular as with the premium.

 

Well debunk things more often and Ill say it more

Ethanol Enhanced Gasoline yields 75-85k BTU's per gallon, Pure Conventional Gasoline yields 108-117k BTU's per gallon.

 

and that is why you get better mileage. btu is a measurement of heat energy. the higher, the better.

 

Yup your not going to get much out of premium for an engine that is mechanically designed (8.8 to 1 compression) for regular. And the computer is factory tuned for regular gasoline as well. If you could tune the computer for premium so that it would adjust for it you might get something. I pulled my intake manifold and cleaned out the head with a soft toothbrush and marvel mystery oil. At 200,000 miles she purrs now with cheap 10% ethanol regular gasoline. You probably getting the cleaning quality and the lack of ethanol out of the premium fuel. I'm sure it won't hurt you at all though.

It is my understanding that higher octane gasoline is less volatile then lower octane gasoline. Giving it the ability to be compressed much more then regular gas before it will detonate allowing you to get more power out of it in a high compression system. By compressing it more you are storing more kenetic energy, when it is sparked you get more out of it because it is compressed more. If you have a lower compression system like the jeepster then it really does nothing, except provide you with a better quality fuel. I have never really seen a difference in any fuel I buy, but since I've got this engine running so smooth now I'll have to give it a shot and see whats up for myself.

 

premium vs regular - the battle rages! As I said in my earlier posts, premium will give a slightly better mpg, but not much. It only does this due to a lack of ethanol in it (as stated by others). IMO, the best way to clean and smooth out your engine is the #4 option I suggested. The only reason to run mid-grade or premium afterward is to lower the amount of carbon build up in the engine due to the fuel burning cleaner. The lower amount of carbon build up allows the engine to run smoother for longer.

I never run Sea Foam through the TB - it's just too risky. I simply take the TB off and thoroughly clean it with carb cleaner. Same with the intake manifold.

Overall, the "advantages" of Premium are NOT worth the cost increase. Running an occasional tank of premium is good for your engine as it helps clean it out a little, but taking stuff off and actually cleaning it is far better.

 

Premium does burn cleaner?
Premium gets you better mileage?

I fail to understand why that would be. I appreciate everybody that experiences vast improvements, but being an engineer who used to be involved in engine design, I would lover to understand the more scientific explanation why this is? Admittedly, it's been quite a while since I was involved in this sort of engineering, but it seems great strites of improvements have been made since!

Jeroen

 

zetzkj, I have a difficult time understanding why you felt it necessary to rant about down home talk?

 

I run Shell Vpower through my jeep because if I don't I get pinging (preignition?) when climbing hills or accelerating. My cylinders probably have higher compression because of crud buildup, and what I probably need to do is take the thing apart and clean it out thoroughly. Seafoam through the gas tank didn't make the ping go away, but increasing the octane did. I can't say it increased my mpg at all, but it's cheaper than an engine teardown.

 

I think most of this just boils down to 100% gasoline gets better mileage than 90% gasoline and 10% alcohol.