Gas mileage way down

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Old 03-25-2009, 12:57 AM
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Gas mileage way down

I know there are probably a bunch of these but i searched and didnt find much.

I have a 2001 Supercrew F150 with the 5.4 in it. It has 105,000 miles on the motor. Oil changes have always been done every 3,000 miles. As of lately the gas mileage has started dropping it is now at 9.4 mpg mixed driving. It has cat back exhaust, cold air intake, and programmer. The truck is lifted with a three body lift and has 35" tires and 3.55ls. I used to get around twelve mpg mixed driving with the same setup but know i need to regear.

It is still on original plugs and cop. I know these need to be changed i have them on order but what else besides regearing do i need to do to get better gas mileage.

Thanks, any question just ask
 
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Old 03-25-2009, 01:40 AM
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Wink .

with a 3 in lift 35's and heavy wheels u wont get any better than 12 mpg. u can do a few things. try cleaning the intake with a cleaner through the manufacturer and make it breath a bit better. Wat are your shift points on your programmer? maybe a little high for more hp..
 
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Old 03-25-2009, 01:55 PM
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did you program the tire size into the computer? as said before the tires will bring the fuel mileage down some. but you just do the current tire size / the stock tire size x the mileage driven / the number of gallons used= fuel mileage.

other than that you could still do some maintenance to it. like the plugs(use motorcraft), fuel filter, clean the air filter if needed, clean maf sensor(oil fom filter could get on it and cause false readings).

and other than that you may want to upgrade to 4.10 or 4.56 gears.
 
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Old 03-25-2009, 04:45 PM
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yes it has been reprogramed for the tire size. i think migdaddy misunderstood i used to get twelve like it is now but it has dropped to 9.4 mpg. i would be happy with twelve again.
 
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Old 03-25-2009, 04:49 PM
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what kind of programmer? i'd do a tuneup with that many miles. and how long has the K&N been on it? i'd clean the maf sensor too.
 
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Old 03-25-2009, 05:48 PM
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What kind of gas are you using? Gas with high ethanol content will drop your mileage.
 
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Old 03-25-2009, 07:09 PM
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what kind of service has been done?

may be time for a coolant flush. you know the plugs and coils need to be changed. air filter. might even clean the throttle body.

all the little things add up.
 
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Old 03-26-2009, 12:23 AM
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Originally Posted by Matts ford
what kind of programmer? i'd do a tuneup with that many miles. and how long has the K&N been on it? i'd clean the maf sensor too.
Hypertech programmer. By tune up you mean plugs and cop? Air filter is cleaned regular for got to mention that

Originally Posted by glc
What kind of gas are you using? Gas with high ethanol content will drop your mileage.
Try to use nonethanol but sometimes use up to 10% but to tell u the truth no matter the differences between fuels i get the same within 5 or 10 miles total on 26 gallons of gas.

Originally Posted by chiefFX4
what kind of service has been done?

may be time for a coolant flush. you know the plugs and coils need to be changed. air filter. might even clean the throttle body.

all the little things add up.
regular oil changes and fuel filter changed every six thousand miles. Could coolant cause a drop?
 
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Old 03-26-2009, 12:28 AM
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You should get about 10% less with the ethanol. Everyone else does.
 
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Old 03-26-2009, 07:11 PM
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Put a can of seafoam in the fuel, it will clean the injectors better than any other fuel injector cleaner on the market. I'm not saying that is the problem, but it can't hurt. I have an 86 Bronco (5.0/ FI), wouldn't hardly run. One can of seafoam helped a bunch. Keep in mind if your injectors aren't dirty you won't notice a difference, if they are you will also feel a power gain. Good luck.
 
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Old 03-27-2009, 01:42 AM
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BG44K is better than Seafoam.
 
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Old 03-30-2009, 09:30 PM
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What is BG44K? Never heard of it. Where do you get it?
 
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Old 03-31-2009, 02:39 PM
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Old 03-31-2009, 02:44 PM
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Fill the tires w/nitrogen.
 



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