I want to get a exhuast system. I don't care if it's loud or not, I'm just looking for a few extra horses and better fuel efficiency. Any suggestions? I have a '97 F150 4.6L auto Extra cab longbed. Would it be worth it to get new headers, highflow cat, etc, or just get a cat-back? Thanks in advance.

 

my exhaust didnt give me any better mpg, but it sounded good, i had a 40 series but now a 50 series because the 40 was too loud towing, the intake like a K&N SYSTEM dont just get the filter, or an airaid system will give you 1-2 mpg beter

 

cool. Already got a cold air intake with a K&N. I should probably just buy a Honda CRX as a daily driver if I want to save on gas. $200+ a month on gas sucks when you only make $20k/year. I have been eyeballing the 40 series. I rarely tow and I like a throaty exhaust, so I might just go with that. Thanks for the reply.

 

If yo want a chance to improve fuel economy, get a muffler with a straight through design. Baffles slow down the air. I have never heard of any performance improvements from any Flowmaster owners. They just like how it sounds. If don't care about sound and just want better fuel economy, try underdrive pullies and electric fans.

 

i got a 40 series flow put on my 4.6 and got 1mpg difference i get 19.5 instead of 18.5 but i get on it some too.

 

1 mpg more is still makes a noticable difference to me

With 19.5 mpg, you can now travel 24 miles farther per full tank, compared to when you had 18.5 mpg.

...and if you fill up 4 times a month, that makes a estimated total savings of 5 gallons per month or travel 96 miles farther per month compared to before.

...which makes a savings of a whopping 60 gallons per year!
If you pay around $1.75/gallon, 89 octane, like i do, that would make an average savings of $105/ year.

 

i've got 40 series Single in/Dual Out on my '99 with the 4.6 and my mileage has dropped down to 8-10 mpg. The guy at the local ford dealer told me since I had less backpressure now, my exhaust is running cooler and throwing off my exhaust temperature sensors, which now tell my engine to burn more gas. He also said my thermostat could be stuck open and throwing off other temp sensors. I hope somebody can steer me in the right direction here because I really don't want to have to go back to stock exhaust, i LOVE the sound

 

i dont know i have a 4.6 and i get better gas milege, did you take your cats off?

 

My entire truck is stock, except for a Clarion HU and a cold air intake. Since I changed my oil, installed Bosch Platinum +4's, and cleaned my K&N, I'm back up to 16 MPG. Once I stop working 7 days a week, I'm going to change my fuel filter. That'll probably help. Oh yeah, I'm getting a hold of Borla Cat-Back setup for cheap. Hope to get it and have it installed by next Friday. I'll post sound clips, if y'all would like?

 

I've gone up 2-3 MPG with my intake and exhaust.

 

no, everything from the cats back was replaced...I still get pretty decent mileage going around 60, but going from stoplight to stoplight is where it really kills me... Anybody else have a drop in K&N??? mine seemed to give me great mileage to start with, but it's not as good now, even though I've just cleaned it.