My 04 FX4 gets 13 in winter mixed hwy driving, maybe 14.5 in summer. That's with 3.73 gears.

Last summer I ran a test for a full month by switching to 91 octane with no ethanol, and I averaged 16.5. I get similar numbers when I'm out west hunting and can get away from government mandated ethanol.

Ethanol sucks.

 

I wonder if the increase in fuel mileage was as a result of the 91 octane, or no ethanol?

 

Probably both - but the lack of ethanol is a bigger factor.

 

2009 Platinum 6.5' 4x4, 3.55s and I routinely get 12-13 city/highway mixed. Even on 15 hour road trip I only got 14.5 at the best point. When gas went over $3.45 I decided to drive my 2000 Toyota Corolla

 

Seems like most are barely cracking the low end of sticker specs.

 

I normally do not have a problem getting at least sticker mpg's. This truck has been up and down. But seems to have been getting worse as it gets more miles on it.
First year was holding a solid 14 around town. The road trip to Fla. last summer on way down was as low as 15 on highway. Yeah started out running posted highway speeds until lower NC, SC & Ga. They were flying. Just had to keep with traffic. It was hot 94 +.
Now, on the way home running not above 70 it held a steady 18.
Go figure. Love the truck, was hoping for a little better mpg.

With the price of gas now, most likely won't take the road trip west this summer.

Thanks for the info guys.

 

Where in South Jersey are you?