I just bought a 2010 f-250 with the 5.4L. I have not been able to get better than 12mpg's on the hightway... Is that normal? Is there anything I can do to improve that? I put a K@N cold air intake in, but really didn't seem to help at all. My previous truck was a 03 with the 7.3 diesel in it. Loved it, 18-20 consistently everywhere. I went to a new gas, because I couldn't justify the cost difference between the 2. Maybe I was wrong? Any help would be much appreciated, thanks!

 

Drive it more, reset your calculator, and try again. I have never gotten 12mpg out of mine.

 

Are you saying you have never got better than 12mpg? What do you get consistently?

 

I get 19-20mpg on the highway, but our gallons are larger then the US gallon.

That would be around 16 miles per US gallon.

It took 15,000 miles to get the best mileage too.

Oh, and I hand calculate every so often to check the gauge accuracy.

 

16 city, 18.6 highway at 65mph. Hand Calculated... Mine is a 6.4 PSD though. I didn't notice the first time that you said you had a 5.4l. I had a 2008 F150 with the 5.4, and got 17mpg at 65. The F250 is a lot heavier truck than the F150, so I could see you getting around 15mpg at 65mph.

 

Thanks guys! I wonder what mine has going on? I thought the K@N cold air intake would help, but I really didn't see any improvements.

 

I have owned 2009 f250 v10 fx4 4x4 since Oct 09 I am getting an average of 14.6 mpg. I have got 18 going from West Yellowstone to Bozeman downhill and 15ish on the way home.

 

Are you pushing 90mph?

You have it lifted? Oversized tires?

 

My 2010 f250 4-4 with a 5.4 averages 13.5. The guage in the dash shows 15.5 on the highway.

 

hate to say it but the K@N kit was a waste of money..

the stock airbox/motorcraft filter is just as good..

 

I average about 13.5 mpg hand calculated. I can get 14.5 on long highway trips.

 

I do have different tires, and rims... I put 20's on it, but it is not lifted. I don't drive any faster than normal.

 

What axle ratio?

Come on --- you don't expect us send out government agents to inspect your vehicle before we render an opinion?

If you put bigger tires on it, and did not recalibrate the speedo, there is a big issue right there.

 

I average 11.5 around town.....its a truck.....not a hybrid.

 

My 2010 5.4L F250 4X2 CC SB gives 12-14mpg city and 16-17~mpg 70mph flat interstate in central Florida. The DIC is about .5 mpg optimistic. Rolling hills and rush hour knock it down a bit.