I just bought an 07 F-150 XLT 5.4L from an auto auction and have a bit of a drive to work. I am looking to improve my gas mileage and need some tips on how to do so. Next Friday I am having cat-back Flowmaster duel exhaust installed and I am also going to install a K&N Cool Air Intake. My main question is whether or not K&N is the best cool air intake I can put on it and what other type of modifications I can make to improve its mileage.

 

I have a 2001 Ford Crown Victoria..
I have installed high flow cats and 3x18 glasspacks necked down to fit the dual exhaust
K&N filter with a modifyed air box
E3 plugs and home made water vapor injection
also running 180 deg. thermostat
my mileage is 27 highway
you might try these mods on your ride

 

grandpabobby... E3 plugs and home made water vapor injection .. Would love to see pics of that vapor injection system...

how does the thermostate help save you gas? Just curious...

 

Please, Please beware of lower temp t-stats; these can be a real problem. If the CHT sensor says that the engine is never getting hot enough, it injects a little more fuel, which can take the catalysts out over time.
These engines are designed to run at about 195-200 degrees, so that the emmissions are reduced the best they can be.
And it's not uncommon for a car body to get better gas milage then just about any truck; trucks have much lower rear end ratios, which aren't availbile in the cars.

 

It's a whole new ballpark with the engines running at higher temps.
I must agree with greasemark, he gave you some good advice.

 

The computer goes into closed run at 170 degrees 180 deg thermostat will not effect the computer..running the engine a little cooler will help it live longer..you only need 195 in areas where it gets very cold in winter
Google water vapor injection..they do work !

 

Some will go into closed loop around 140 and some others go into closed loop as soon as the O2 sensor hits 600 degrees. They are doing everything to get the computer to begin fuel control ASAP because of emission requirements they even throw in some extra "pre converters" to help accomplish this.
I believe one of the reasons for the higher temp thermostats was to assist the burning and get rid of the hydrocarbons that stayed on the cylinder walls and eventually came out the tail pipe. In many states with strict emission laws and state inspections a low temp stat caused a hi HC readings just as over advanced ignition timing did.

Even Ford says, "80% of engine wear occurs on a cold engine".

So many things have changed it is pretty difficult to stay up with it all.

 

check the thermostat ! if the thermostat is not the right degree it takes then that will cause it to drink gas ! did you check the air filter ? matter of fact it might need a complete tune-up !

 

OK, I stand corrected. I just work on them. You're right.

 

the best way to improve mpg is don't drive it like you just stole the damn thing. in other words if it ain't a hot rod then don't treat as such and if it ain't broke don't fix it or try to make it any better 'cause if you do then you're gonna F!@#& it up put slightly taller tires on it and drive it normally