I have a F 350 4x4 5.4 super cab it has a flowmaster exhaust I get about 10-11 mpg would a KN air filter give me better gas mileage?

 

welcome to FTE! i dont know if that filter will or not!

 

Well I got about that much reg driving last summer if I drive like a little old lady i can get 12 but i cant so it gets 9to10 good luck

 

I get up to 16 MPG with mine, but adding a K&N air filter didn't improve the mileage.

Driving style will help.

 

i read in another topic that the k&n filter was real bad for turbo, since they don't filter the air as much and may let damaging material through, don't know i don't have one, but i would do some research first if i were you.

 

Welcome to FTE!

Quick answer: NO.

First...you do not mention what year SD you have?
Stock size tires?
What gears you running?
How many miles on your SD?
Is that 10-11mpg in city or highway driving?
Have you done all the scheduled maintenance???

Keeping your 5.4L in top running condition...and an easy foot will yield the best for mpg.

biz

 

I pulled my k&n and put a reg. filter back in , no difference in mpg or performance , but you could always see dust in the intake tube !

 

I never notices a difference running one either. The whole intake system might make a difference but you're talking some bucks then. Not many upgrades are going to give you a significant jump in fuel economy. My problem is I see them as 'performance upgrades' not fuel economy upgrades. More horses means you can put your foot into it more often right?

 

I have a 5.4 SC, SB, 4x4 and I get 16 mixed driving. My truck is bone stock. Maybe it's my 3.73's and 5-speed auto that make the difference.

 

the truck is a 2003 F350 5.3 liter 4x4 super cab with flowmaster exhaust stock 16" tires that I just bought with 13K miles on it. I get 10-11 miles a gallon. I will add a KN air filter hoping to get better gas mileage.

 

when i bought my truck .... the first tank of gas prob 87 octane ... i got 11 mpg.. mixed driving.....
after that i had a super chips programer and a K&N full cold air intake, and Aero turbine exhaust system (no cat) ..... eventually added a topper, fender flares .... and now finally a functional ram-air hood intake.......(among other things that that dont really effect mpg other then maybe weight?) ......

so after all that ...i still only average 13 mpg ..... with my mixed driving

during the winter ive dropped to about 12.5

i havn't tried it on a long trip all hwy yet (since the ram air) to see how that does.... i dont seem to take long trips with just the truck very often .. as i'm usually towing on long trips...

and yes.... im glad i did all that stuff ... as the truck "feels" so much better....

.....really....... there isnt alot u can do about mpg other then driving habits IMO...

 

I certainly know little about the mechanical aspects of a truck. But maybe the problem is a 350 with a 5.4 V8. I have a 250 crew with the V10 and get 12-13 city, and 15 to 16 on the highway (depending on speed limit).

 

I think you might have hit the nail on the head there. Nothing against the 5.4 guys but my simple logic says a bigger motor takes the same or less fuel to move a big truck than a smaller motor working harder to do the same. Yes I realize there are tons of factors like driving habit, gears, weight, etc. but that's my thought.

 

Just a waste of your money, but it is your money. The only benefit (and it doesn't even out way the downside)...is that you get a 1,000,000 mile filter that is re-usable. Just make sure not to add to much oil to the filter because it will dirty up the MAF sensor.


biz

 

i have a 2000 CC 4x4 shortbed 5.4 auto 3.73's, dual exhaust all the way back, no cats, 40 series flowmasters, and i just put a K&N in and made a 600 mile trip the next day, with my speedo showing 80mph with my 305's it ended up at 14.9mpg which im sure is really better, what I could tell the most was my truck took a little longer to downshift going up hills and might not downshift on every little uphill bump in the road i came across.