just picked up an 08 supercrew 5.4. do you need to cycle a couple of tanks of gas thru it before you can figure out what your realistic gas mileage will be?

 

you will get a hair better fuel mileage once it breaks in. i check my fuel mileage every fill up just to make sure i'm getting the same as i have been. just make sure you keep up with oil changes and tuneups you'll have no worries.

 

it's gonna be a small fortune filling up the 35 gallon tank!

 

its pretty expensive. i can never actually fill up the tank if its close to empty, it always cuts off when it hits a certain price.

if you just bought the truck, you might not want to look at the mpgs. it might be depressing. enjoy the truck, and try not to think about it. haha.

 

the sticker showed 18mpg.......i'm sure they didn't account for the extra weight of the 35 gallon fuel tank...that can't help the gas mileage with the extra weight, and it has the 6.5 ft. bed, adding more weight also

 

I have heard for years that gas mileage improves as you drive it and it loosens up. Now that I have GPS running along side the speedometer I have noticed that as the tires age the speedometer thinks it is traveling 1% faster and farther that it really is.

If your truck sat on the dealer's lot for months and you have E10 gas in your area, then you'll want to run a few tanks through it.

 

The ford hand book says...
Breaking period first 1000 miles,
After 3000 miles you can work out your true mpg,i just past 3000 miles and im getting 19mpg and my truck is a heavy beast.

 

I'm at 5k and getting about 19 - 20mpg according to the dash readout but I think it's .5 to 1 mile less per gallon, at least thats the way it comes out when I do a manual calculation.

 

average-joe and bkdamon.....what type of mileage were you getting in the first month?.......if i can get miles per gallon you guys are getting after the break in period that would be what i was looking for.

 

I was getting 18mpg on avg first 3000 miles, my truck is a XLT 5.4L 163" wheelbase supercab.
Now after the breakin period, im getting 19mpg.

 

This is my mileage chart this year. Nothing spectacular.

 

if i get anywhere around 19 i'd be happy!

 

well when you think about it all depends on how you use your right foot whether your crazy with the throttle or just an easy cruiser, cuz i have dual exhaust with purple hornies and when i see a chevy showin off i can't help but show em who's boss haha but thats just my opinion.

 

I was getting about the same. I'm very easy on my throttle and use cruise whenever possible. I usually run 65 on the Interstate and 60 or less on secondary highways.

 

I have a new (bought 1 1/2 weeks ago) 2008 F-150 XLT Screw w/ 4.6 L V-8. 18" wheels. On a trip to St Louis and back last week, driving 70-75mph, a few times hitting 80mph when passing, I got between 16.5 and 17.5 MPG. Not sure it will ever be any better, But.. it's a great truck and I plan to keep it at a long time.