When I picked up my new rig from the dealership, it was mentioned that using higher octane fuel may actually decrease my MPG and it was recommended to use 87. But, it seems from reading some of the posts, with a chip involved those owners are running higher octane fuel. Is this something that is required in order for the chip to perform optimally? How about without a chip, will running 89 or 92 octane hurt my MPG?

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2001 F-150 4X4 ORP
Green Super Cab XLT
5.4, 3.55 LS
Mods soon to come!

 

All performance chips require higher octane gas!!!! 92 octane minimum and 93 is better. Octane booster is not recommended. I don't think higher octane without a chip will reduce your gas mileage. The Ford computer can learn to use premium after a few tanks but if you don't get a chip just run 87. Good luck and I think Mike Troyer will respond with more details to help you.

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1999 F-150 Lariat SC 2 WD, White/Silver, 5.4L, 3.55LS, K & N FIPK, Superchip, underdrive pulley set, Flowmaster dual chamber one in and duels out, six disc CD changer, towing package and captain chairs

 

You know what kill's me, is that i called jet performance and asked them what i should run in my truck with there chip, they said 89 octain,well i guess that explains why that chip dose not do a hell of alot, pretty sad!!!
When i installed a hole new high performance computer in my Dodge Ram ss/t 360, you had to run 94 octain, and belive me if you didnt, you would know it, Ping like crazy. Thats why i will be buying a superchip, alot of good feed back on it .

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1999 Ford F-150 xlt .supercab, 4x4 sport pkg. 4.6 Triton, Black with grey int,A.R.E. Lid, ford bug deflector,Q-Forms,eclipes head unit,and speakers,kicker solo's for subs,1000 watt amp. Flow master 70 series, K&N drop in,jet chip .will be geting a superchip.

[This message has been edited by 4 wheeler (edited 01-15-2001).]

 

Hi Stifford,

Welcome to F-150 Online!

Very common question, and very appropriate.

Your owner's manual tells you to use 87 octane because your factory programming has tuned that engine specifically for the burn rate of 85-87 octane gasolines. Using higher octane with the factory program can cause driveability problems in some cases, which is why they warn you about that in the owner's manual.

Higher octane fuels have a slower burn rate, or the speed at which the kernal of the flame front propagates itself in the combustion chamber, and so if you use premium with the factory program, you can actually get a soggy throttle response and worse performance sometimes, we've seen it work both ways. Meaning, if you use premium for long enough, (at least 2000 miles in the 1999 & newer Fords), they can pick up about 2% more peak power, but even so, the ECU can never properly utilize higher octane fuels without being specifically reprogrammed for their use, as it's the burn rate that must be compensated for in numerous areas of the program.

We have seen posted here both increases and decreases in mileage here from the people who have reported back their results using higher octane fuels with the factory program, but over the long haul, we've seen more decreases than increases over teh past couple of years here when using premium with the factory program. The ECU simple cannot take proper advantage of higher octane fuels without being specifically reprogrammed for the use of higher octane (via the Superchip), so it's a waste of money to use anything more than 87 octane with the factory program.

When you install the Superchip, it re-tunes your engine specifically for the use of premium gasoline, you're no longer running on the factory program, so there is no problem using premium gas with the performance chip, it's required, in fact, as that is how most of the additional raw power gain is made.

So the rule of thumb is, use 87 octane with the factory program, and premium gas with the Superchip.

If you'd like to go over this in more detail, please feel free to give us a shout, & best of luck with your truck!

------------------
Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com
Performance Products F150Online Superchip ordering system: F150Online Superchip Ordering System
First National F-150 Online Rally Event Organizer

 

Thanks for all your help and thoughts guys. There is a lot more to the newer trucks than most people (myself included!) would ever think about. I look forward to talking with you more Mike.

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2001 F-150 4X4 ORP
Green Super Cab XLT
5.4, 3.55 LS
Mods soon to come!

 

Mike.. are you saying on a stock truck
there is absolutely no benefits running 92 octane?

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97 F150 4.6 v8 longbed
_ _ _ _ _______ _ _ _ _
K&N Air filter
K&N FIPK TECH MOD & REMOVED ELBOW SILENCER
_ _ _ _ ______ _ _ _ _
Hyper White xenon bulbs
_ _ _ _ _______ _ _ _ _
Bedliner and Raven Shell
_ _ _ _ ________ _ _ _ _
6 disc cd changer

OIL & FILTER USED Mobil 1
_ _ _ _ _________ _ _ _ _
Gas used TEXACO & CHEVRON

 

Hi Moose-man,

Excellent question, that isn't a simple yes or no answer, at least on newer FoMoCos. What I'm saying is that it's basically a waste of money use anything more than 87 octane with the factory program F-150, and most other stock vehicles that only require 87 octane from the factory, as the Ford ECU has extremely limited capability to do any adaptation for premium fuel. In a number of mid-90's & later Fords, you can pick up as much as a 2% increase in peak horsepower by using premium gas for a long enough period of time, but you'll still never have as good overall throttle response & driveability using the factory program in an F-150 on premium gas as you will with 87 octane. It's due primarily to the different burn rates of the fuels, which is why most owners manuals tell you to use only 87 octane, and many mention specifically not to use premium gas, to this very day. It's all due to potential driveability issues that arise as a result of premium gasoline burning slower, and so the fuel curves must be reprogrammed to compensate for the burn rate, so that driveability doesn't suffer. While you can potentially pick up as much as a 2% peak power gain @ WOT (wide-open throttle)from using premium in a late-model F-150, that tells you nothing of what happens the rest of the time you're driving, as we spend very little time at full-throttle.

When you use premium gas in a computer controlled vehicle that is programmed (tuned) for 87 octane, you can sometimes get a "soggy" throttle response, worse driveabilty, and worse mileage, as the fuel curves are programmed for the quicker burn rate of lower octane fuels. Now this isn't something that is usually "drastic", but if you pay attention to those kinds of things, it can be noticeable, which is precisely why Ford says not to use it. Unless and until the factory program is altered specifically for the use of premium gas, it's a waste of money to use premium in most vehicles tuned for 87 octane from the factory.

Fuel mileage, at least in our experience, does not go up just by using premium gas, unless the actual energy content in the premium gas was higher than that of the regular gas previously being used, and that can and does happen of course.

One very funny thing is that last year Ford put out a press release, announcing that they had just designed in a brand new feature that allowed some of their new vehicles to increase power when using premium. It was nothing new at all in reality, it started in the mid-90's in many FoMoCo vehicles, and the maximum potential gain is only 2%. And they *still* put that warning in the owner's manuals to not use premium gas! It was nothing new at all, yet they claimed that it was something brand new, a breakthrough, etc. So at that time, we predicted that the owner's manuals in forthcoming model years would still have that warning not to use premium, and we were right, they *still* say that.

The bottom line is, as long as a person is not getting detonation using 87 octane in their stock vehicle, it just doesn't make much sense to spend the additional money for premium gas, other than perhaps in a few cases potentially better detergent additives in higher octane fuels, unless you install a performance chip. The benefits just aren't there, and driveability can suffer as a result of using premium with the factory program. Not always in every case, but it can happen, Ford has certainly seen a lot of cases like that, so consequently they tell you not to do that in the owners manual.

------------------
Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com
Performance Products F150Online Superchip ordering system: F150Online Superchip Ordering System
First National F-150 Online Rally Event Organizer

 

GOOD info mike...Thanks!
i will fill up with 87 next tank and see what happens..
if i get pinging ill go back to 92!


------------------
97 F150 4.6 v8 longbed
_ _ _ _ _______ _ _ _ _
K&N Air filter
K&N FIPK TECH MOD & REMOVED ELBOW SILENCER
_ _ _ _ ______ _ _ _ _
Hyper White xenon bulbs
_ _ _ _ _______ _ _ _ _
Bedliner and Raven Shell
_ _ _ _ ________ _ _ _ _
6 disc cd changer

OIL & FILTER USED Mobil 1
_ _ _ _ _________ _ _ _ _
Gas used TEXACO & CHEVRON