I had a superchip installed on my truck for a few months and i did not see an improvement on mpg(read no superchip better performance). I have sent it to superchips to be looked at, but what i want to ask to anybody is this, how is anybody getting 17 and 20 mpg? Even when i drive on the freeway i might get 16 mpg. I do not have a heavy foot or go above 65 or 70 mph.I keep on seeing and reading posts that talk about this improved mpg and i am just at lost trying to figure out what is wrong with my truck. My best mpg with supechip might have been 15 mpg, now without it after 6 fuel tanks is about 15.5 so no big improvement.But still if anyone can tell me if they have or are having the same results as i, please, let me know.

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99 xlt sc,4.6 2w.d.,gibson catback,
superchip,
rsx shocks,
hellwig sway bar,
3" front lift,275/70/16 scorpions,
sst soft bed cover.

FUTURE MODS:4.10 GEARS, GORHINO BRUSH GUARD AND HELLA LIGHTS.
From: Los Angeles, CA

 

You might want to hold off on those 4.10s if you want better MPG.
Where you live has a lot ot do with MPG.

 

my trucks a manual 5 speed. I think that too helps me get 17mpg. Plus using a good brand of gas helps also.

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97F150 XLT SC 4x4 Flairside 4.6 V8 5sp Dk Toreador Red, 3.55LS
ARE tonneau cover, p255/70rx16 tires (came w/235), Superchip
Pioneer CD w/4 Polk Speakers & Clarion APA5240amp, skid plates
bed liner, side window deflectors, reese hitch, K&N air filter
40s-2chamber Flowmaster, Bosch +4 spark plugs, rustproofing
Better Built Stainless nerf bars

 

Know what you mean. I had one of the first 97 model Fords sold in Sulphur, La. I ordered the truck in August of 95. Got the truck in Jan. 96. BIG MISTAKE... That truck got 13 mpg no matter what I did. It was a 4.6, 3.55 ls, sc. We changed the ecu, reprogrammed the new ecu, Hyperteched it, did everything I could think of, still 13 mpg. Traded it in on a 99. Strange happenings, 99 Lariat, sc, 5.4, 3.55 ls, tow pkg,loaded. Was getting about 16 mpg hwy, Superchipped it, flowmaster, K&N filter, now honestly get 17.5 to 18.5 hwy. I am thrilled with the difference. I nor the dealer know what the problem was with the 97.
The only thing that I did that would change the mileage on my 97 any at all was to change the brand of tires. Michelin tires got the best mileage on that truck. I put 90,000 miles on that truck, so, I had plenty of time to play with different setups on it. You might look at trying someones stock size Goodyears, swap rims and tires for a few hundred miles. Also, are you figuring for your larger diameter tires? This will affect your mileage numbers. You are actually traveling further than your odometer reads, if you have larger than factory tires.

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I don't know why but I have always had decent gas milage. I purchased by 1999 in June and it has 2800 miles on it now. My first tank of gas yielded 16.5 mpg the last 3 tanks yielded 18.8, 19.2, and 19.3. ( I know running the A/C cuts my milage by 1-1.5 mpg) I have auto, 4.6, 3.55. The lowest mpg was last month when my lead footed wife borrowed the truck ( 16.1 mpg ). She is the only person I know who thinks the person in front of her is only there because they need to be passed by her.

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99 XLT SC, 4.6 L,MacNeil Window Deflectors, Ford-Duraliner Bedliner, K&N Filter, Westin Nerfs.
Family Hauler


[This message has been edited by OrangeburgFord (edited 10-09-1999).]

[This message has been edited by OrangeburgFord (edited 10-09-1999).]

 

I think it is great that you guys especially
OrangeburgFord get such great gas mileage. I read these type of posts all the time and am continually amazed!

veloci, I dont have the superchip, but I have tried several other things to improve my MPG, but to no avail.

I'm lucky to get 14mpg. I'm not lead footed, but I will get on it sometimes. I guess I just have to be happy that my Ford looks better than those other manufacturers!

------------------
1999 F-150 Supercab Flareside Sport Package
Oxford White Full tint Bug shield CD player, 17" wheels, K&N
Ford Soft Tonneau cover
Gibson Super Truck Looking for more!

 

IMHO, My 99' gets better gas mileage and performs better than my 97' { same model}

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Fast46Triton

1999 Ford F150 XLT Supercab, Shortbed, 4x2, 4 wheel disc brakes/4 wheel Anti-Lock Brakes, Cloth Seats, Amazon green, 16" All season tires, Soft Tonneau Cover, CD Player, 4.6 liter Triton V8, 3:55 ls, towing package, 4 speed auto, K&N Airfilter
Future Mods:
1)Superchip
2)Airbox Mod
3)Gibson Exhaust

 

>>>>Been averaging 14.6 mpg around town, recently took my truck on vacation from Virginia down to the Florida Keys and got 17.6 mpg. I was really pleased with that all things considered. Eventually hope to get a superchip, with thoughts of more improved mileage and h.p.

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99 F150 XLT SC 4x4 4.6 liter Deep Wedgewood Blue

Westin Nerf Bars

Lund Bug Deflector

Kenwood 10 disc CD changer

Bodyguard Bed Liner

 

Well all I get with my truck is just 15.5 to 15.7mpg.


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~
1999 Ford F150 XLT 4x4
Off Road Package
Tow Package
5.4L Automatic
Supercab
Electric 4x4 switch
Full bench interior
Factory running boards
Mods : superchip, gibson
swept-back exhaust, k&n
FIPK. Bug deflector.
Use : Mobil1 5w30 and
k&n oil filter.

 

hey you guy's should be happy. i have the v6 and only get 15. w/o romping on the pedal. i got 16 mpg when i first bought the truck but now i think the gas stations may have switched the blend of gas for the upcoming months of cold weather. now it's 15 in town and 15 on the highway.


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'97 f150 rc, flair side,4x4,v6,5 spd, k&n air filter

 

Dear Veloci,

Well, you have a couple of complicating factors that we have discussed over the phone, but are not being mentioned here in this thread. First, you are running considerably larger tires than stock, and that forces your engine to work below it's power band, because it effectively changes your gearing. Anytime you do that, you have to give it more throttle than you normally would, and the engine is working harder than it normally would, and thus, using more fuel. A gearing change is in order to compensate for this.

Second, you have a 3" lift on the front of the truck as listed in your signature line, and that is just aggravating the effective change in gearing that happened when you installed the larger tires, by raising the profile of the truck further up into the wind.

What we suggest for those contemplating larger tires sizes is to take a tape measure and measure the circumference of the tires you have now, and of the tires you want to use, and make sure the tires are mounted and inflated to correct pressures when you do these measurements. I suggest using a seamstress' cloth tape measure, it's much easier to work with. Compare the difference in circumference between the two tire sizes, and if it's more than about 4% or 5%, you will need to do a gearing change to avoid forcing your engine to operate below it's power band.

Given all the circumstances at work here, which many reading this thread wouldn't know since they weren't part of the phone conversations between Voloci and myself, I'd say you're very lucky to be getting the gas mileage you are! From our conversations, you are dealing with about a 9% increase in circumference, and that's a lot.

The Superchip adds power, that is very true, but it can't make up for circumstances that require a change in differential gearing.

Anyone who wants to avoid all the work of measuring and calculating tire circumferences, etc., can just give the good folks at The Tire Rack a call, and they will help you out with these decisions. I don't have a number handy, but they have a website at, I believe, www.tirerack.com

Our bests to all,

------------------
Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com

 

Veloci,
I also have a California truck and I seem to get much worse mileage than what others report. I've got a 2wd V-6 XLT Supercab w/3.55 gears and I get 15.5 - 15.8 mpg every tank. My foot is heavy, but not that bad! I've only got over 16 mpg once, and that was all highway with a tailwind. People with 4wd 5.4 liter autos are claiming 15 mpg!

I ordered the superchip but had the no start problem. Can't do without the truck to send my circuit board off to Superchips, and my resident soldering expert (dad) had a heart attack and is out of commission, so my chip is sitting in its box. Can't wait to see if I get the 2 mpg to 3 mpg improvement claimed by some members.

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1999 XLT S/C, 4.2 V-6, auto, 3.55 rear, dark torreador red/harvest gold, bed liner, Sony 10 disc CD, Edelbrock IAS, K&N filter, soon to Superchip

 

It's weird how much the mileage differs between trucks, even accounting for driving styles. Two weeks ago I did a 300 mile trip of which the hiway part was in the mountains of Colorado. I put 135 miles of the trip off road and at the end of the trip I got 16.33 mpg. Hardly ANY of this trip was on the horizontal, even on the hiway. I leadfoot this truck constantly, usually running 3,500 - 4,000 rpm before shifting. Am in the process of checking the mileage around town now as I have orderd the superchip and I want to see what the difference in mileage is...

------------------
Mike Boardman '99 F150XLT 4X4 RC,FS,4.6,5spd,3.55LS,ORP,
Towing pkg,K&N GenII FIPK,FLowMaster,SnugLid,Luverne Nerf bars,
bug shield, DK Toreador Red.
When everything's coming your way, you're in the wrong lane.

 

I have the v6 5spd, and average 15 in town and get between 17/18 on the highway depending on my lead foot.

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99 F-150,XLT, Silver, 2WD, 4.2L, 5spd, RegCab, Shrt WB, Styleside.
Current Mods:Billet grille, Line-X bedliner, 5%window tint all the way around, Alpine CD w/2 MTX Subs & Rockford Fosgate 250w amp. K&N Airfilter. Glasspac w/dual exhaust exits out the back. Blue Ion Headlights.
Future Mods: Superchip, driving lights, & a custom paint job

 

Thanks for all the replies. But so tire size does not become part the picture, this is what i did: i went from 245/75/16 to 275/70/16 there is barely a 2% differential so that is why after giving some thought i decided not to change gears. As i read these posts i can only say that i am very happy with my truck i just want to make it better like the rest of us. I will wait for superchips findings in regards my superchip and i will take from there. Again, like always, thanks for all the input.

------------------
99 xlt sc,4.6 2w.d.,gibson catback,
superchip,
rsx shocks,
hellwig sway bar,
3" front lift,275/70/16 scorpions,
sst soft bed cover.

FUTURE MODS:4.10 GEARS, GORHINO BRUSH GUARD AND HELLA LIGHTS.
From: Los Angeles, CA