ecoboost poor fuel economy
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Joined: Jun 2005
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From: Louisiana
I replaced my factory tires with the same size BFG Ats and I've lost .5 mpgs , 2011 Eco with 373 s , I get about 1.5 better mpgs with non ethanol gas , also truck started getting better fuel economy after 5k miles, average this tank is 17.4 mixed driving
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From: Joplin MO
I cheated - I went into your garage and saw your location as "NS" which I believe is Nova Scotia.
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Joined: Nov 2003
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From: ME
Rotating mass can make a big difference. With my 34" tires on stock 20's I was averaging 15-15.4 MPG's before cold weather. Since cold weather and winter blend fuel it dropped to 14.5 MPG's. Those averages are driving conservative most of the time.
Since I plan to take my truck to the drag strip a couple times this summer.I picked up some lightweight rims/tires because the 34's would kill me at the track. They are 2005 17" chrome clad wheels (Plastidipped)w/ 265/70/17 tires. They are a ton lighter than my stock 20's w/ 34's and much lighter than my stock 20's were with stock tires. The other day I put them on and tried them out. I drove pretty conservative on the highway. But every time I took off I was flogging it pretty hard. I also practiced my boost launches a couple times. When I got home my lie-o-meter was reading 18.4 MPGs. I know the mileage is slightly off because of tire size but it picked up some MPGs even not babying it like I normally do.
But she sips fuel and goes like hell. The fuel mileage is great but I'm ready to put the 34's back on. If I don't do it soon I won't have any tread left on my drag racing tires.
Here she is, she ain't pretty.
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Joined: Jan 2012
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That was on a trip using all the fuel milage tricks I could stand.
Last edited by Snowflake58; Feb 26, 2012 at 08:02 AM.
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From: willow glenn
my 07 supper crew with 5.4 3;73 with a 3" leveling kit and 35" supper swamper's got better than the OP Eco boost. hell my 2010 5.4 screw 3:55 gets better than 12.5. its not much better but it is better
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Joined: Oct 2009
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From: Mechanicsville, MD
As mentioned earlier you have a taller tire and more importantly a heavier tire. It takes more power to get that heavier tire going. If I had to guess I would say your truck is actually in boost alot more than it would be with the smaller tires. Get yourself a boost gauge and try to keep it in vacum. Everytime you spool those turbos up you are using alot more fuel.
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Joined: Apr 2008
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From: Buckhannon,WV
I have a 2011 F-150 Screw EB with 305/65/18 BFG A/T's weighing in at 66lbs a piece off the rim. My mileage is averaging 12.5. Doesnt matter what engine someone has, if you run bigger tires, chances are they are heavier than stock, therefore mpg will drop. I bought my EB for the towing torque, not the mpg. I guess it all goes along with the saying, "You wanna play, You gotta pay"!