Well i just got home from a 300 mile trip.

anyway about 175 miles of the trip was flat and i had it at cruise control on 65

the other 175 were kinda hilly and going over one mountain pass and had it at cruise on about 75

by the time i pulled into my driveway, my truck computer said 15.2 mpg and my gryphon said 15.1


what im confused about is people like FishChris who said towing his boat he gets 16 mpg.

heres the modifications i have done to it

2008 Ford F-150 Lariat Supercrew 4x4
True Dual magnaflow exhaust
Gryphon programmer
33' BFG A/T's 18" XD monsters
K&N CAI


City driving which is 95% of the time i only average about 12-12.5 mpg and never really get above that

i drive pretty conservatively too, no rabbit starts. I also do live in Seattle which has alot of hills but i would think i could get better than 12.5

now i didnt buy my truck to get good gas mileage but i just wish i could get some better mpg than i am getting

 

wow, at times i get better city mileage than you. I can pull 13.0-14.0 with a light foot. Other than that we have the same city mileage about, my average is 12. My best highway mileage has been 15-16, i breifly pulled 17.5 with the wind at my back I bet if i pulled a trailer around we could throw gas mileage under the bus and say less than 10mpg.. The area I live in is also very flat, with lots of wind...damn panhandle of Texas and west texas winds

 

What gears do you have? You're gas mileage sucks, if you're running 3.55 cause you have 33s and 18s, which are way heavier than stock.

 

i have 3.73

 

True duals, do you have an X pipe?

 

yes i do, and custom tunes with the gryphon

 

Hm, all I know is, I had a 400 mile road trip, with 3.55 and I only got 15.9. Have you done the calculations yourself?

 

yes always and i enter everything in ownersite.com which comes up the same as my calculations.

i had planned on doing a e-fan and UD pulley mods but jeez ive already spent so much on mods that havent done anything

 

You have a 4x4 which is heavy, you raised thr front end which eats into mpg and you have heavy tires which get you bad. Your mileage is not all that bad, considering. There are no mods that will pay for themselves in gas savings. The mods you have done make it perform better, but really don't save too much.

 

My truck only gets 12.5-13.7 mpg no matter if its mostly highway or a mix of city and highway and its all stock.

 

that is your problem man

I lived across the water in Silverdale for almost 6 yrs. I feel your pain. In that neck of the woods, you don't ever truly get Highway driving.


My 06 Screw averaged about 14-15 mpg mixed driving out there all the time. Your not really gonna get much better MPG until you get out of those damn hills.

When I drove to Texas and back, I was easily breaking 18 mpg to 21 mpg once I hit the flat states. I loved driving across Kansas, Oklahoma and Texas. Don't think I got a single tank below 19 mpg in them

 

Have you figured that your odometer is incorrect due to the oversize tires? You actually go further then a mile even though it only reads one mile. So if all you do is transfer the odometer readings. Then they are wrong.

 

He has a tuner, I would assume he calibrated it for the tires.

 

It is the tires....They are heavy and it makes a huge difference.

Ryan

 

good point