Okay Guys help me out with this one. Just got back from our trip to the beach and I'm a little worried. This has been the fourth time the X has made this trip and I'm off around 4 mpg. Set at 70mph on the downhill run from Atlanta to the coast I have always got around 18mpg. This trip I was seeing more like 14.5mpg and 14 on the way home. Air and fuel filter have less than 5K on the both. Have these 285 BFG AT cut my mileage this much? I could see may be 1-2 mpg but 4?
My first thought was air filter. You mentioned you had only 5K on it...but really, it all depends on how much dust you encounter. For instance, here in Houston a lot of the freeway construction crews use PSD trucks, but they have to change out their filters at least once a month.
So you may want to check the condition of the air filter (don't rely solely on the filter minder).
Also, check your fuel bowl itself to make sure there's not a bunch of crap in the bottom. You may have gotten a batch of bad fuel sometime before your trip. It's also good to make sure you've been draining it periodically for water separation.
Just a couple of quick thoughts from me. I'll let the real experts think up the more complex possibilities...
...yep, and also, the tires, on mine the 285's actually corrected the speedo. Either way, if you jhad them installed since your last trip and didn't confirm if the speedo if on or off, you're travling further than your computer thinks you are so it calculated the MPG wrong showing it lower than it really is. Hand calc would be the same thing.
Can't tell if you have a 6.0 or 7.3 but it's usually simple and easy (depending on your dealer) to correct the revs per minute.
__________________ 2004 EB Excursion, 4x4, 6.0, everything but step tubes and 2nd row chairs, Magnaflow Exhaust, Isspro Gauges in an under cubby pod, Fumoto sitting on V Codes and Revo 285's.
"Treat me good, I'll treat you better; treat me bad, I'll treat you worse." - Sonny Barger
I assume your mileage is off. When I changed to 285s it put my mileage off by 3.3%. So, start there. In addition, I assume I lost 1 to 2 mpg with the bigger tires.
By the way I never got 18 mpg going 70 mph by hand calculations. I have seen 20 mpg on the computer if I stay at 60 mpg but I can't get that. If I stay at 70 I think I would have gotten 17 mpg with the OEM tires.
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2000 4x4 PSD Limited Excursion The Beast
DPTuner 40Tow, 60Tow, 80Econo, BTS Valve Body, AIS Intake, AIH Delete, MBRP Stainless 3.5" DP and 4" Exhaust, 5" All spring Edge lift, Rize Traction Bars, CV joint driveshaft, 315 BFG ATs on Alcoa wheels, Warn Transformer with multi mount winch power front and back, 1000 watt power inverter, VCR, 4.10 gears and ARB Lockers Front and Back
Will pop the hood and give a look at air filter. Fuel bowl was drained when I changed the oil about 2 months ago, but will drain it when I'm under the hood. Other than a GPS how can one check their odometer? Are mile marker accurate enough? Stop watch and flat section of highway with cruise set?
Okay yall busted me, I have NEVER seen 18 mpg cruising at 70. It averages around 17.5-17.7, and since we CAN round 18 feels better than 17 point something. [img]/ubbthreads/images/graemlins/grin.gif[/img]
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Will pop the hood and give a look at air filter. Fuel bowl was drained when I changed the oil about 2 months ago, but will drain it when I'm under the hood. Other than a GPS how can one check their odometer? Are mile marker accurate enough? Stop watch and flat section of highway with cruise set?
Okay yall busted me, I have NEVER seen 18 mpg cruising at 70. It averages around 17.5-17.7, and since we CAN round 18 feels better than 17 point something. [img]/ubbthreads/images/graemlins/grin.gif[/img]
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Do you think you might've filled up with Diesel #1 or some blended version of Diesel #2? Can't say that I've seen the blended versions of diesel a whole lot that far south, but it could be possible. In the winter time when Diesel #1 is required up here to prevent gelling, I see at least a 2 mpg reduction in fuel economy...running stock tires.
Did you get your speedo recalibrated after changing tire sizes? (the PCM needs to be reprogrammed with the correct rotations per mile of your new tires, this can happen even going with the stock 265 tire size because not all tire brands have the same revs per mile in the same size) [img]/ubbthreads/images/graemlins/shrug.gif[/img]
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Whip
'02 Ford F-150 SuperCrew FX4
fabtech 6" suspension lift, pro-comp traction bars, nfab nerf-steps, weld racing typhoon, summit mud dawg 315/75R16, flowmaster 40 series dumped, clear eyes, euro clear corners, 100w off road lights, alumistinger draw bar, manik brush guard, flex-a-lite 270 electric monster fans
I've got a 2002 with the tire recall
I haven't had my tires changed yet, I'm actually planning on going to the firestone dealer and getting the Steeltex in load range E from them cause I really like them.
How would I get the ecm reprogrammed to fix any speedo error after the tire change when I run the Superchips micro tuner, every time I take it to the dealer I put the stock tune back in
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