Increase fuel milage - Ford Forums

08-27-2003, 22:07

I just purchased an '03 f150 Lariat with the 5.4 liter motor. I can get about 19mpg on the highway and 14mpg on the street. I had heard that if you change out the stock mufflers with flowmasters and change the air filter to a K/N you can increase you fuel millage by a couple of miles per gallon. Do you know if that is indeed the truth? With the gas being almost $2.25pg in CA, I would like to get the most out of it.

Thanks,

--Jeff

351w · 08-27-2003, 22:21

cant say for sure if you would get better milage around city or not but mufflers and a filter would deffinetly boost HP and probably take a tenth or 2 off your 0 to quarter mile time.
that would be real helpful on friday night shootin out those ramps on the way home.
whenever you make any changes that allow an engine to work more efficiently you will see some type of gain, whether it is seat of the pants or at the pump i say go for it.

89F150 · 08-28-2003, 01:08

cant say too much either but i will give you one tip. Keep your foot out of it.
but to back up what 351 said, the more efficient you make the vehicle the more hp your going to get and possibly better fuel effiency as it doesnt have to work as hard

08-28-2003, 08:38

Thanks for the help. I think I'll go get the Borla Cat back and the K&N filter. Do you know if I replaced the intake system to a K&N would it void my Warranty? I have a 100K mile warranty and I don't want to jepordize it.

Thanks!

big1 · 08-29-2003, 10:44

The exhaust and K&N will diffinently help your milage, but you can go one better. If your area allow's it by law, you can also install a zero or low back pressure "CAT" this will further improve the breathing of your engine. Which if you don't change your driving style will improve your milage. There is a cold air intake system also available for this truck that will also help. Sorry, but I can't remember the manufacturer.

89F150 · 08-29-2003, 18:48

Is it air force one or air raid, something like that big 1? i think there cold air, i'm not sure now.