What's probably happening is that when you buy the 90 you're getting an honest 87.

When I cared about every ounce of liquid going/coming into/outof my '97 I believed that I got better mileage with premium than with regular -- at least the difference of the price of the fuel!

Well, I'm resigned to lousy 13.5-14.5 mpg with Nick -- and use the cheap stuff -- and he runs simply great!

My buddy's 5.3 has start-up valve clatter that would make me blast the radio for the first 5 seconds if it were mine -- but I believe him when he reports 16.5 to 17.5 mpg with it (rode with him for 200 miles Monday/Tuesday -- and the thing rides nicely -- but I like Nick better).

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Y2K™ Jim

Toreador Red, Keyless XLT SC SB 5.4L E4x4 4wDisc/ABS, 3.73LS, Skid, HD 7700# Towing, LT-245's on Chrome, Tube-Steps, Captain's, 6CD, Tonneau, named: "Nick"

 

I have 5.4 3.73 4x4 auto, K&N only, and always get 14-16, mixed driving (80 mph on hwy). I usually have the AC on and tend to floor it quite a bit to pass slow drivers. I also have piston slap and leaking head gasket - maybe that's the trick to better mileage! I actually expected worse with 3.73 gears and my poor driving habits.

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firstimeFord
99 SC 4x4 5.4 3.73LS

 

High Performance exhaust won't help your MPG unless you drive the truck the same way it was driven before the mod. I think most people want to hear their performance exhaust, so they drive their vehicle in such a way that it produces the most noise. At least that's been my past personal experience.

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1999 F150 4X2 SuperCab, 4.6 (Romeo). TuTone White/Gold, Bedliner, Prime Designs Bug Deflector, Ventvisors. No cracks, no Engine Mods, no Problems.

 

GEE YOU GUYS ARE LUCKY IF YOU CAN GET 90 OCTAIN FOR THE SAME PRICE AS 87. OUT HERE THERE IS NO SUCH THING, WE HAVE 87 , THEN 89 WHICH COST .10 MORE PER GALLON, THEN 92 WHICH COSTS .10 MORE THAN THAT PER GALLON. SO WHEN THE GUYS IN CALIF. SAY YOU CAN FEEL THE DIFFERENCE BY THE SEAT OF YOUR PANTS YOU KNOW WHAT WE MEAN. I'M CONSIDERING A CHIP BUT HAVING TO BUY PREMIUM GAS AT .20 MORE PER GALLON WOULD HAVE TO REALLY SEE A BIG DIFFERENCE.

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'97 F150 4.6L XL WHITE,FLEETSIDE R/C L/B, LEER SHELL W/FISHING POLE RACK, BED MAT,LIMMITED SLIP,245/75/16 DESERT DOGS ON POLISHED ALUM, WHEELS.
AIRAID, 3" CAT BACK OUT THE SIDE w/MAGNAFLOW MUFFER

 

It's been a while since I've posted, so bear with me. I've been averaging 11-13 mpg. I made a trip from Columbus, OH to Myrtle Beach, SC and I averaged 13 mpg over 3 tank fulls (didn't even think about running the A/C though). Considering my Harley in the back and a 4x4, not too bad, but it could always be better. I used 89 octane and ran about 70-80 mph the whole way. The best I ever got was about 20, no lie (big tailwind and no traffic). Anyway, day to day, I get about 11. I have to deal with the morning and afternoon rush, so I'm getting killed at the pump. It sounds like we're all getting close to the same kind of mileage. Well, that's all....

On a 2 side notes... My girl friend and I made the same trip in her Civic, and we spent round trip in that what I spent one way in my truck. Go figure..

If there are any bikers out there, I highly suggest going to M.B. Bike Week. This year was my first, and I plan on making it every year. Very good time. Lots of bikes, beer, and women. What more could you ask for??

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1998 F-150 XLT 4x4, Regular Cab, Short-Bed, 4.6L V-8, 5-Speed, 3.55 Rear Gears, Dark Toreador Red

 

HERE'S A SOMETHING TO CONCIDER. I HAVE A 1999 F150 5.4 AND I MY ENGINE HAS A ROUGH IDLE/ENGINE MISS AND I GET AROUND 11/12 MPG. AND THATS ANYTIME (TRAILER OR NO TRAILER). SOME OF MY COWORKERS HAVE IDENTICAL TRUCKS AND ARE GETTING 17/18 MPG AND THEIR TRUCKS RUN GREAT. MAYBE ITS A COMMOM PROBLEM BETWEEN THE ROUGH IDLE AND THE MPG. ANYONE ELSE HAVE THE SAME PROBLEM?????????????????

 

On any new or used truck or car, you should always change the plugs. They are never even gapped close from the factory! Knowing how the plugs on these trucks are not the easiest job, not many people change them as needed. Get them gapped with some fresh plugs and that should help the milage. If you have over 40K, time to change wires also.


About the only modification that is sure to increase the MPG is an electric fan. Less drag on the engine frees more HP and you will get better milage.

 

I forgot to mention that I always get 14-16 on 85 octane, that's the "regular" grade here in Denver. I tried mid-87 and didn't notice any difference in mpg or power, only in my wallet ($.15 more than 85). Mine doesn't ping, even when towing, so I guess it's ok.

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firstimeFord
99 SC 4x4 5.4 3.73LS

 

Matt90GT, Plugs are another area that can use attention. Using the ring&pinion calculator the other night I found with 3.55 gears and the slightly taller tires I put on my truck at 60 mph the engine would be doing 1655rpm and with the stock tires 1733rpm. They say optimum range for a small block v-8 is from 1800-2800 rpm. So even from the factory in overdrive you are lugging the engine some at 60 mph, I can really feel this when I pull a grade. So for the people thinking of buying a new truck I would say order the 3.73 gears or maybe even 4.10 if you are thinkin of much larger tires. now if you travel a lot of flat roads at 75-80mph you probably will do great with 3.55's but I usually have to get 3 counties away from L.A. area to do that.

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'97 F150 4.6L XL WHITE,FLEETSIDE R/C L/B, LEER SHELL W/FISHING POLE RACK, BED MAT,LIMMITED SLIP,245/75/16 DESERT DOGS ON POLISHED ALUM, WHEELS.
AIRAID, 3" CAT BACK OUT THE SIDE w/MAGNAFLOW MUFFER

 

What kinds of mods can I do to improve the MPG without reducing the power? exhaust? air filter?

I went to the EPA's web site and they stated that the higher octanes will not give better MPG. Only use the higher octanes if your truck needs it or starts knocking.

I get around 15 MPG city and 17 MPG highway. I heard this may be higher MPG than old 150s because of a new construction technique. I only have about 500 miles on it so I do not know if it will improve a little as the engine breaks in. I also drive conservatively, but I like having the power in case I need it.

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2001 F150 Lariat SuperCrew 4x4 with 5.4L V8, 3.55 Diff
Other: Moonroof, sliding rear window, bed extender, keyless & remote entry, cab steps

 

Electric fan, that will free some engine HP up and save some gas.

 

Forgive my automotive ignorance but what fan? The one at the front of the engine. Isn't that powered by the belts? How would you go about modifying that?

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2001 F150 Lariat SuperCrew 4x4 with 5.4L V8, 3.55 Diff
Options: Class III Trailer Towing Group, 4x4 Skid Plates, Electonic Shift on the Fly, 17-inch 10-spoke cast aluminum wheels, Moonroof, sliding rear window, bed extender, keyless & remote entry, cab steps, Line-X bedliner