Another MPG question....
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Joined: Dec 2006
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Another MPG question....
I picked up a '01 F250 SC shortbed (stock 3.73 gears for now) that has a 6" lift and 35"s. I know the lift/tire combo is going to drop the fuel mileage, but I'm curoius if anyone knows of a formula or something to figure out just how bad. Bottom line, the reason I'm curious is I've had the truck for 2 months now and really no matter how I drive it (ie. heavy foot, mostly freeway miles on one tank, mostly city miles on a tank, etc..) my MPG has been a pretty consistant 8-8.5. This is my second V10 and the previous one was a '99 and the exact same truck just without the lift and 33"s and I would get a consistant 11-12 MPG on that. So the 8-8.5 I'm getting now seems just a touch lower than maybe it should be.
BTW, I do paper calculations for MPG (ie. top off tank and reset odometer then divide miles by how much gas I fill up with next top off)
The truck has 49,000 miles on it and I plan on changing the fuel filter and spark plugs soon for peace of mind and to see if that helps at all.
Finally about the gears, I'm planning on 4.56s. I was planning this just to get some more performance but could the truck see a little better gas mileage not having to work so hard to get moving?
BTW, I do paper calculations for MPG (ie. top off tank and reset odometer then divide miles by how much gas I fill up with next top off)
The truck has 49,000 miles on it and I plan on changing the fuel filter and spark plugs soon for peace of mind and to see if that helps at all.
Finally about the gears, I'm planning on 4.56s. I was planning this just to get some more performance but could the truck see a little better gas mileage not having to work so hard to get moving?
Sit. Stay.
Joined: Oct 2001
Posts: 18,308
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From: Washington State
I think your odometer is off by like 11% with those 35's. Add 11% to your MPG and I would say you're right in the ballpark for a lifted truck with bigger tires.
I think your new gears may actually help with MGP a tad.
Never heard of a formula to try and come up with MPG projections for a lifted truck. Too many variable, I guess.
I think your new gears may actually help with MGP a tad.
Never heard of a formula to try and come up with MPG projections for a lifted truck. Too many variable, I guess.
Elder User
Joined: Aug 2006
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From: Enterprise, Al
yeah from stock the 35s will throw the speedo off a good bit especially at highway speeds so with that you should be around 10 which still seems low to me i get 10-12 on mine with 16" of lift and 44" tsls
i would definetely check the plugs, air filter,fuel filter and clean the maf
i would definetely check the plugs, air filter,fuel filter and clean the maf
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Thanks for the replys guys. Yeah I agree, I knew the speedometer was off by some (didn't know how much) so I thought MPG may be a little better than calculated, but still thought it was a touch low. Realisticly, if I'm at 10 and I squeeze 11 MPG out of my truck I don't think the extra 26 miles would make me get too excited, but every little bit counts right?
Another thought, I put a K&N FIPK intake on when I got it. Does the Ford ECM read that the engine is running lean with the extra air and compensate with more fuel? I've had cars in the past that were sensitive enough to do that but, like I said, my '99 had one and it didn't seem to hurt mileage so unless Ford modified the ECM by '01 I would assume this isn't the case. Mostly thinking out loud....
Anyway, new plugs and fuel filter will go in this weekend so I'll see if that helps at all.
Another thought, I put a K&N FIPK intake on when I got it. Does the Ford ECM read that the engine is running lean with the extra air and compensate with more fuel? I've had cars in the past that were sensitive enough to do that but, like I said, my '99 had one and it didn't seem to hurt mileage so unless Ford modified the ECM by '01 I would assume this isn't the case. Mostly thinking out loud....
Anyway, new plugs and fuel filter will go in this weekend so I'll see if that helps at all.
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tutone
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Aug 26, 2008 07:59 PM
