Alright I usually get about 260 or so miles to the tank. My gauge can usually go about 60-70 miles between each quarter on the tank. For the last few weeks I have been getting about 200-210 miles to the tank. I got that before I put the 32's on. I drove home to DE and I got the normal mileage, but when I drive around to work and everything, my mileage has been sucking. The bad mileage started when the Gas light came on and I filled up with 14.4 gallons, when I usually only put 12.2 when its empty. Do you think all that gas could have contaminated something? I have put fuel injector cleaner, gas treatment, everything and nothing works. What can I do? Yes it is still under warranty.

It got that mileage even before the lift. Plus i hope I wouldn't lose 50 miles because I am a little taller.

I got the bad gas or so I thought the week before the lift, drove home with normal gas mileage to DE and then get bad mileage once I get back down here again.

 

Forget the per tank mileage.
What is the actual difference in your MPG??
That is the only true way to figure gas mileage.
And you need to get three representative 'fill ups' under the belt for comparison.

 

I used to get about 20-21 mpg and now it comes out to ~17.5. I know my speedo is off by around 3-4mph, so I am not sure how much that will change my mpg.

 

that might do it... is it because of larger tires?

 

32's. I just did not think that it would throw off the calibrations that much and my mileage would reflect that dramatically.

Could I still be getting the same mileage, it just reads less?

I wish I could get a hold of Apten so I could reburn my chip.

 

i would think your milage would be about the same but its reading different because of the tires... my 92 did that when i put larger tires on it

 

If I can't get Apten to respond, I need to know where I can get my speedo recalibrated at.

 

I get abotu 17mpg with my 2002 4x4 with 32" toyos. (4.0 auto though)

 

Also don't forget that when you put that body lift on you left your battery unhooked long enough for the ECM to forget all of the previous settings so it is probably still trying to tune the mixtures back to optimal. Also having just the lift and tires will drastically change your perception because I have a 3" body lift w/ 33" BFG A/T's and every 100 miles the odometer registers is actually 120 miles. If you do highway driving note the odometer at a significant mile marker XX0, X25. X50, etc....and see just how far you are really going....

 

I don't know about that ZetaOmegaRanger, my odometer is reading 103 right now and its at half a tank, and I usually get 175 at half a tank with the 29s or 31s I had..I have 33s now and off by about 72 miles now...I don't floor it at all...I just have to get it recalibrated soon, and one of my buddies at a place is going to let me know if they can do the speedo for me soon..I didn't think that it would be off by that much...

 

Algebra will tell you that is wrong. Going from a 245/75 r 16 tire (about 30.5") to a 33" is an 8-10% increase in tire size (the range is due to tires not being exact sizes). So the change should be more from about 100 miles to 110 miles. I calculate my gas mileage on the same 8% change and I get about 18-19 mpg.

To the original poster: Are you calculating the mileage/ odometer offset correctly? How many miles are on your truck? Air filter clogged? Fuel filter need replacing?

 

def check ur air filter

 

It only has 31k miles. The air filter is clean, just cleaned it. I have no idea if I need to replace the fuel filter. I want to take it to Ford, but I don't want them bitching about the lift and all.

I went from 245's to 265's. I used to hit around 160-170 at the half tank mark and now it might hit 100-110. I know my speedo is off by atleast 3 mph, because my buddy in his new gmc paced me when we were coming back from home. It only driving around town that it suffers really bad, I got 21 mpg when I went home last weekend(400 miles) and I usually get around 20mpg around town, but now its down to 17-17.5 mpg.

I am getting my speedo fixed when I send it to Apten in a week.

 

Well I just got my speedo recalibrated and it wasn't off hardly at all.
Speedo-Actual:
25-23.5
35-34.5
45-44.5
55-56.9
65-67.5

The guy at the dealership said that the mileage could be off that much b/c of the larger tires. But I only went up one tire size, how in the world could I lose almost 4 mpg. Still confuses me because I got 21 mpg on the 400 mile drive home and back with the 32's.

 

Ford recommends changing the fuel filter at 30k, but I don't think one thousand miles over is going to make a big deal, unless you got some really bad gas from somewhere.

Dealerships don't usually give a rip about aftermarket stuff, unless you are trying to get warranty work done on a part damaged by the equipment. A fuel-filter replacement isn't going to be covered under warranty, as it is a "wear-n-tear" item like brake pads.

What gears are in your truck? That may make a huge difference.
EDIT I just saw in your sig you are running 4.10s. Your highway mileage should actually increase, so that is not it.

 

I might have gotten some bad gas, or put too much fuel in the tank when I somehow put 2 more gallons than usual in the tank. How much does a fuel filter run and how hard is it to change?

I was looking at my service manual dvd and it looked really easy except for the releasing the pressure in the system.

 

Bigger tires also mean more rotating mass which also will affect your milage. Not just speedo calibrations.

I'd bet summer has alot to do with it too. Driving with the A/C on, more hot, humid air, etc will detract from efficiency.

 

But the thing that kills me is that I got regular gas mileage when I drove home(400miles), I got 21 mpg then. I always got the same mpg when I drove around town too. But now I only get about 17mpg around town. I am not seeing the correalation here.

 

Fuel filters are around 30 dollars. They aren't hard at all to change, and I didn't even bother releasing the pressure in the lines. Just watch out, because it'll spray a little bit of gas, but not enough to bother releasing the pressure for. Just wear some glasses or goggles or something.

 

I know some people who would kill for 18mpg around town... I think yours is normal.

I get 20mpg on extended trips and 17 in town with my 4.0 and 32" toyos
(4x4 of course)
still changing the fuel filter cant hurt its time anyway.
Rand

 

I am impressed I think my computer has finally got accustomed to the new tires and I am now back up to around 20 mpg. Wahoo. Can't wait to get home and drive my baby. I am in Lousiana for 3 weeks and it sucks not having anything to drive around in.

 

I average between 18 and 19 with my 32's... My speedo Is still off, so It would Prpbably be about 20mpg

 

Everyone seems to forget that with bigger tires, you're actually going further than your odometer reads.

when I went up from the stock 28" tires to 32" tires, I did the math, and basically I'm going 1.1 miles for every mile the odometer reads, so when I stop to calculate my gas mileage, first I multiply the mileage on the trip tick by 1.1, then divide by the gallons I used.

Really its pretty good being non-corrected... I know how fast I'm really going, so the speedo doesn't bother me, and I'm putting about 10% more miles on the truck than the odometer shows. So basically running 32"s uncorrected is getting me 10% more warranty miles. :)

 

Yea, but I got my speedo corrected by Ford. I just can't wait to get home and drive her.

 

The PCM will adjust fuel trim to "optimal" almost instantly. It is constantly adjusting it based on the information it receives from various sensors. We're talking seconds here so that wasn't a factor in your economy.