FrdTuff

I just bought my 2010 FX4, flex fuel with 80k miles, two days ago. The previous owner installed a cold air intake. Everything else, except the headlights, seems to be factory. The truck was bought at auction by the dealer and it came to the states from Canada, as a good majority of the trucks in my area do. The night I bought the truck it read 10 mpg average. I figured this was from me romping on it a bit as its a new to me truck. I reset it and drove normal all day yesterday, mostly city. I filled it up and it estimated about 525 miles for that tank. Now it says I'm getting about 13.5 mpg. I read these trucks average 18-21 mpg. What could be causing me to get such low gas mileage???

bign1497

Are you tires bigger than the stock that's printed on the door pillar. My 2011 was getting 19.5 mpg before I went to 33" tires and then dropped dramatically. Part of the decrease was due to incorrect speedometer cal. and part due to tires changing ratio of gearing.

FrdTuff

No, they are stock 18" rims :-/

bign1497

Is the TIRE size what's printed on the pillar?

brianw0048

iTrader: (1)

2014 STX 5.0

The 14mpg readings were running flex fuel. Per tank readings, not per short trip. 36 gallon tank. Stock size 20s running MasterCraft Courser AXT (heavier than stock).

21RRF150

iTrader: (1)

First thing I'd do, is don't believe the truck. Calculate by hand. My 2010 mpg reading is always way off than hand calculated.


Second thing. Unhook the battery, let it sit for 15 minutes. This will reset everything from the previous owner. The trucks computer and transmission with then learn how you drive after.


My 2010 gets about 19 mpg's mixed. I use 100 % gas though

FrdTuff

Thank you! I will try this when I get home

FrdTuff

What app are you using???

FrdTuff

I will check here in a bit but they look like standard size tires...

brianw0048

iTrader: (1)

fuellog for android.