With gas prices in BULL **** range, I am now buying 87 octane gas. Is there an good fuel additive I should use, and how often?

 

your trucks were both designed for 87... you should be running 87 to begin with, otherwise you're just pissing money away. Unless you tuned them for something higher, in which case, just revert them to the stock tune or take some timing out of whatever tune you're running.

is there a reason you weren't buying 87 octane?

 

I think my engine sounds better with higher octane...

 

well, that is the sound of not getting a complete burn out of your higher octane gas... octane is flame retardant, the higher the octane, the slower the gas burns. Your engine was designed for 87 octane, and only allows a window so long/short to burn the required amount of gas. 87 octane will be more violently exploding than 91-93, and thus the explosion will happen faster, push the cylinder down harder. higher compression engines are designed to compress that air/fuel mixture more and thus get the same violent reaction out of higher octane gas. tuned normal engines will ignite the higher octane gas sooner, so that it has time to fully burn. If you're running high octane into a non-tuned vehicle that's designed for 87, you're simply pissing your money away. You're not gaining any power, in fact, you're probably losing some; and thus, some MPG too.

you always wanna run the lowest octane you can get away with basically.

 

Thank you very much for that explaination...With that logic are additives a waste of money?

 

depends on the additive. if you're talking octane boosters, yeah, 99% of them are. The only ones I've seen that work well are the Torco concentrated race fuel line; the only reason I know they work is basically people using them sucessfully with their forced induction cars and race gas tunes - but only on pump gas and the torco additive. Again, they wouldn't do anything on a car not tuned or not needing that kinda gas tho.

I was stuck in BFE once with my mustang that needs 91, and only 87 was available (new mexico...)... the people in the gas station looked at me funny when i bought all of the octane booster they had on the shelf... my car still pinged on the way home if I got on it this was after about 9 bottles dumped with about half a tank of gas... so yeah, they don't do anything IMO...

Additives that clean stuff do help, though not as much as professional cleaning - mainly injectors - it's generally much better to take it in for a professional cleaning job where they hook up the injectors and run concentrated cleaner through them, rather than putting the stuff in the tank every fill up.

 

 

Higher Octane+99% of Fords=Waste O' Money.

 

That is the best math problem I've seen in a while!!!

 

I have had this exact same thing happen to me. Except my car is tuned for 93, and all I could get was 89. Now whenever I go on a road trip, I take a couple of bottles of octane booster just in case.

 

I thought this was a forum for 2007 and newer Expeditions.....Why is a contributor with an 8 year old Expediton making any comments, or no comments. Maybe there is an older Expedition site you can throw your 2 cents in.

 

Sorry, but I don't own a newer Expy either. I was just wondering about octane and thought I would respond here. I have a 95 F150 with a 5.0 and if I run 87 in it, it will ping on the highway when running the AC. I run 89 in it. All 3 F150s (85 351, 95 4.9, 95 5.0) I have had did this as well as an 89 Mustang. All of these vehicles were run on 89 instead of 87, to eliminiate the pinging.

 

As stated before, you could adjust the timing, and then the vehicle would run on 87. No harm done, except for 10 cents more per gallon.