2005 Sport Trac - 20MPG (City)!

[CrumpledWastebasket]

Finally completed my 2 year quest to break 20+MPG in my 05 Sport Trac! On the last tank, I got just over 20MPG, with only city driving, and the truck currently has about 110K miles on it.

Thought some of you guys may be interested, so I'll detail everything I did below.

- drilled holes in air box
I drilled many, many holes in all 4 sides of the factory air box, as well as removed the "snorkel". I'm sure you could bypass this step by simply buying a CAI or something similar, but I tried to spend as little money as possible on all of my mods, so I stuck to drilling holes.

- NGK Iridium IX Plugs
Swapped out the factory Motorcraft plugs for a set of NGK Iridium IX plugs. Wires are still the original Motorcraft ones, with approximately 110K miles on them.

- removed the resonator
I feel like this was one of the most important steps. I'm no expert in exhaust mods. Heck, I hardly know anything at all about exhaust mods. But I heard that the mufflers and resonators in the mid-2000's Explorer's were extremely restrictive - so I cut the resonator out, and bought a pipe/clamp kit from O'Reilly to connect the muffler back to the end of the tail pipe. Cost $6.99, plus tax. The sound stayed roughly the same, though it may be slightly more raspy.

- fuel system cleaner, new filters everywhere, new fluids everywhere
I use a bottle of Fuel System Cleaner about once every two months or so. I changed my oil to SuperTech 5w20 (rather than using Motorcraft 5w30 like I had always done in the past), replaced the oil filter with a Motorcraft filter, changed the differential fluid with SuperTech 75w90, replaced the transmission fluid with SuperTech Mercon V, replaced power steering fluid with SuperTech Mercon V, and replaced the serpentine belt. (I also replaced the alternator around this time with an ACDelco 130a model - but I don't believe that is relevant.)

- Performance 87 Octane Tune
Finally, I bought a SuperChips Programmer, and flashed the ECU with the Performance 87 Octane tune. This seemed to give the truck quite a bit more power, but didn't seem to affect the MPG much.

All in all, I spent about $50 doing all of this, if you don't include the SuperChips Programmer. About $410 if you do include it - but I really don't think the tuner is necessary in order to get these MPG results. For the extra 4-5MPG, these mods will take quite some time to pay for themselves. But I happened to have the extra money at the time, and thought I'd take a risk and see if I could hit my goal of 20MPG. So glad that I did - the truck drives like a dream now!

 

[swshawaii]

Respectfully, I don't believe 20 MPG city for one second, especially with those "mods". I'm lucky to get 13-14 city with minimal stopping and starting using only Chevron E10 fuel. On several rare ocassions I've hit 20 MPG highway on relatively flat road averaging 60 MPH with no extra weight. I have done similar mods to yours but do not use cleaners besides Techron once a year. Lowered 2.5" front and 3" rear, removed air box silencer, aFe Pro Dry-S panel, Dynomax SuperTurbo muffler with resonator delete, SCT X3 87 octane tune, Zabteck throttle body, stock 29" Michelin Latitude Tours @ 35 PSI, etc. All fluids are Motorcraft except NAPA full synthetic 5W-30, and Amsoil Severe Gear 75W-90 in the 3:73 open differential.

How'd you calculate?

 

[CrumpledWastebasket]

Respectfully, I don't believe 20 MPG CITY for one second, especially with those "mods". I'm lucky to get 13-14 with minimal stopping. How'd you calculate?

I ran the tank completely empty. Checked the tank for residual fuel, but there was none. I then added exactly 1 gallon of gas, then ran until empty again. The odometer said that I got a few miles above 20. Assuming that was just residual gas in the fuel lines/engine, I was left with approximately 20MPG - maybe a little more.

EDIT: to ellaborate a bit, the odometer said that I got precisely 27.2 miles before running empty for the second time.

 

[swshawaii]

From our 2005 Sport Trac owners manual. (Page 236)
http://www.fordservicecontent.com/Ford_Content/catalog/owner_guides/05p27og3e.pdf

Calculating fuel economy

1. Fill the fuel tank completely and record the initial odometer reading (in miles or kilometers).
2. Each time you fill the tank, record the amount of fuel added (in gallons or liters).
3. After at least three to five tank fill-ups, fill the fuel tank and record the current odometer reading.
4. Subtract your initial odometer reading from the current odometer reading.
5. Follow one of the simple calculations in order to determine fuel economy:

Nice looking Trac BTW. I REALLY like the color matched bumpers and cladding, but I'm so afraid of peeling. LOL

 

[CrumpledWastebasket]

From our 2005 Sport Trac owners manual. (Page 236)
http://www.fordservicecontent.com/Ford_Content/catalog/owner_guides/05p27og3e.pdf

Filling the tank will absolutely ruin your fuel economy. Probably why most people are getting 13-14, like you mentioned. Never fill the tank if your goal is to get good fuel economy.

 

[swshawaii]

Filling the tank will absolutely ruin your fuel economy. Probably why most people are getting 13-14, like you mentioned. Never fill the tank if your goal is to get good fuel economy.

Huh? What's your theory? Can't be the extra weight at 6 pounds per gallon. (22.5 capacity)

 

[CrumpledWastebasket]

Huh? What's your theory? Can't be the extra weight at 6 pounds per gallon. (22.5 capacity)

Prior to these mods, my personal experience with completely filling the tank is that I would consistently get about 1-2MPG less when it's filled (about 13-14). However, when only adding about 5 or so gallons, I would almost always get about 16. 17 if the weather was right. I haven't filled the tank since doing everything mentioned above, though. Next time I do, I'll be sure to update this post if the MPG changes.

Also, I missed your compliment about my truck earlier. Thanks Peeling really is an issue. I've repainted the front left corner of the front bumper 3 times already, and it still peels (as seen in the photo), haha.

 

[crankyjew]

Respectfully, I don't believe 20 MPG city for one second, especially with those "mods". I'm lucky to get 13-14 city with minimal stopping and starting using only Chevron E10 fuel. On several rare ocassions I've hit 20 MPG highway on relatively flat road averaging 60 MPH with no extra weight. I have done similar mods to yours but do not use cleaners besides Techron once a year. Lowered 2.5" front and 3" rear, removed air box silencer, aFe Pro Dry-S panel, Dynomax SuperTurbo muffler with resonator delete, SCT X3 87 octane tune, Zabteck throttle body, stock 29" Michelin Latitude Tours @ 35 PSI, etc....?

Interesting. My truck, with 3" of lift, 33x12.5 tires, ladder rack, custom-fabbed free-flowing exhaust, intake silencer delete, autolite double-platinum plugs gets 13-15 mpg regularly. Seems like no matter how I drive, other than off-roading or towing, I get right in that 13-15 range.

 

[swshawaii]

Agree crankyjew. I'm baffled how the OP can claim that much MPG difference by just having 1/4 tank and nothing more. IMO, the MPG killer with these heavy bricks is accelerating from dead stops, even slowly with a light foot. I've actually seen 7.5 MPG in stop and go traffic. Of course when you're idling in gear and not moving, your fuel mileage WILL suck. LOL

 

[koda2000]

I'm not going to comment on the OP's claimed fuel economy, but one thing I've recently noticed while filling the tank on my '01 ST is that when the pump stops, because it thinks the tank is full (even while set to the slowest auto setting) there is still a lot of room left in the tank.

Last week I was filling my tank because I was leaving town on a trip. I buy gas at our local grocery store, where I earn fuel points, and was paying $1.72 per gallon for regular unleaded. My fuel gauge was reading about 1/4 tank when I started and the pump stopped at around 16 gallons. I then slowly squeezed the trigger on the pump and rocked the truck a couple of times and was able to get another 2+ gallons in the tank before it overflowed slightly (which was never my intention). I then drove about 75 miles before the fuel gauge moved off max full.

My point is that filling until the pump stops automatically and overfilling will make a big difference in calculated fuel economy. I believe my normal MPG in good tune, driving gently, with no mods, 4:10 gears and 35 PSI in the tires is around 17-18 MPG (mostly flat highway driving around 55-60 MPH). Around town more like 13-15 MPG. With a given engine design there's only so much you can do to increase fuel economy.

There was a device sold years ago called a Tornado. It claimed to increase fuel economy drastically. It was a thin stainless steel device that sat in the intake tube before the throttle body. It claimed to induce spin into the air charge. The auto parts store I was then working in sold them, but I'd never pushed them and would even talk people out of buying them ($29.95 as I recall). One day a guy came in wanting one claiming that a friend of his installed one in his 5.0L Crown Vic and was now getting 29 MPG. I called bull on that statement, but the guy really wanted to spend his $30, so I sold him one. I never saw him again. Later I saw the "inventor" of the device interviewed on TV news. When he was asked he said he had no idea how the device worked, just that it did. People can claim anything.

 

[sickwilly]

Nice looking ST. Your theory on less gas in the tank = better fuel economy means my darn gas gauge must read on a curve, because it sure the heck drops faster under the halfway mark than it does above the half way mark.

Might be interesting for you to get a boat fuel flow meter and install it so you know exactly how many gallons you are using.

 

[swshawaii]

For $70 it's tempting, I just don't care for aftermarket "gadgets" in full visibility.

MANY users swear by this device, or the more expensive Scangauge product.

UltraGauge OBDII Scan tool & Information Center
www.ultra-gauge.com

Category - Scangauge
www.scangauge.net

 

[429CJ-3X2]

My 2002 with 3.73 gears gets 13-15 around town, maybe 16 in the summer. It did get 20 mpg on one road trip, but usually gets 18-19 on the same trip. I ease in 2 clicks after the pump stops, which gets it full, but not over-full. My gauge works like sickwilly's - a lot of miles on the top half of the tank, not so many on the bottom half. On a road trip, it will go 100-110 miles before the gauge moves much. My '01's gauge is consistently accurate for the whole range. I've had the '01 out on the highway just once in the almost 3 years I've owned it - pulling a trailer loaded with firewood about 50 miles, and the empty trailer on the return. Half the route was flat and the other half was up and down some big hills. Mileage was acceptable. I don't bother to check the mileage in it.

The filler necks on the mid-70's F Series were designed in such a way that the pump would cut off long before the tank was full. Depending on the pump, it could shut off several times before the tank was full. Proper procedure for getting a full tank was even addressed in the owner's manual.

 

[koda2000]

My 2002 with 3.73 gears gets 13-15 around town, maybe 16 in the summer. It did get 20 mpg on one road trip, but usually gets 18-19 on the same trip. I ease in 2 clicks after the pump stops, which gets it full, but not over-full. My gauge works like sickwilly's - a lot of miles on the top half of the tank, not so many on the bottom half. On a road trip, it will go 100-110 miles before the gauge moves much. My '01's gauge is consistently accurate for the whole range. I've had the '01 out on the highway just once in the almost 3 years I've owned it - pulling a trailer loaded with firewood about 50 miles, and the empty trailer on the return. Half the route was flat and the other half was up and down some big hills. Mileage was acceptable. I don't bother to check the mileage in it.

The filler necks on the mid-70's F Series were designed in such a way that the pump would cut off long before the tank was full. Depending on the pump, it could shut off several times before the tank was full. Proper procedure for getting a full tank was even addressed in the owner's manual.

About the only reason I ever check MPG is just to see if everything looks like it's working normally. MPG's on all my Explorers/Mountaineers pretty much sucks (4,000 lb bricks going down the road) but I don't worry about the MPG much. Too many other pluses outweighing the negatives. If I had all the money in the world at my disposal, I'd buy a Raptor.