K I just bought a 2005 f150 kingranch 4x4 with 5.4 and 68k miles. After market includes AEM intake dry filter, banks exhaust and Taylor helix throttle body. I'm getting like 12mpg or less in town. Is this normal?? I checked with the dealership and they said that truck comes with 100k platinum plugs and advised me to wait awhile since there is no codes and no issues running (a honest dealership...weird I know...) I just changed the brakes and that's literally about it. I have an appointment to get coolant and tranny flush this weekend...any other ideas on what could be causing such crappy mileage? ....only other thing is there is a squeak on the furthers right top pulley it sounds like. (If your looking at the engine from the grill in) but the squeak goes away after like 3 mins of running. Thanks guys for any help!!

 

Any help appreciated guys!!

 

It really depends on how you drive it. If you dip into the go pedal even a little, 12 MPG in town is not unusual. However, the advice on plugs is bad. Change them at 60K. Further, they are known to break. If you are mechanically inclined, you can buy the Lisle tool and do it yourself. Otherwise, it can get quite expensive. Do a search for spark plug on this forum and you will get all the info you need.

 

12 mpg is about right for city traffic.

 

I'm getting 13.4 MPG in the city with 34" tires. What size tire are you running? a 34" tire is about 10% bigger than stock. I am actually getting 12 MPG or something but I factor in the bigger tire afterwards that comes up with the low 13s number.

General maintenance is key. A lot of people noticed a difference when they change fluids (tranny, diffs). Change your air filter and fuel filter. Clean the throttle body. Then see where you are at. These are all cheap things to make sure you are running clean.

Change your plugs now. Mine went at 100,000 KM which is earlier than you are at in miles. I had a bad misfire with the original plugs. Yours are past due in my opinion

 

Ok great input guys!! As far as cleaning the throttle body-should I just remove it and spray it down with carb cleaner? Basically just cleaning the "flap" part on the inside for a lack of better term. (Basically the circle that opens and closes? Also for the plugs-I thought the same and after thinking realized 100k miles is high for any plugs...I found a good write on that as well. I just can't believe this truck gets such crappy mpg. Also I'm running 285 70r17 hankook dynapro mud terrains at 55 psi. Thanks again guys!!!

 

I get 13.2-13.4 highway with my 5.4 FX4. Sucks but that's what it is.

33's, level kit, afe intake, gibson exhaust, edge programmer

 

I get 15+ in city and 19+ on highway....but I baby it

 

My MPG's around town with LOTS of stop and go traffic is about 11mpg. With the winter gas I drop to 10ish mpg's.

 

My 06 Screw Lariat with 231,000 miles averages 12-13 mpg running 325/60/R22. 3 inch level, 1 1/2 inch in the back, K&N filter. I cleaned my throttle body couple of weeks ago. what a difference, was averaging 10mpg before cleaning. Take your throttle body off and clean it, the butterfly as well as the cone. Use throttle body cleaner, not carb cleaner. Also clean your MAF with MAF cleaner as well.