I have a 2000 f150 XLT Supercab, 5.4L, 2WD. I am new to upgrading my truck. I have been hearing that a Flowmaster muffler can help gas mileage. That obviously interests me these days. I also hate how quiet my truck is. It doesn't sound like a truck at all. I'd love to get to hear some of that V8 sound without getting too loud. So I guess my questions are, can I really improve my gas mileage to make it worth the purchase? Will just a single exhaust flowmaster help with gas mileage and performance and give a good sound? Also, what size in and out would I need for my truck? I'm sure it would be nice to upgrade to dual exhaust, but I'm looking to go as cheap as possible right now. Thanks.

 

flowmaster, magnaflow, imco all help gas mileage like 1 or2 extra mpg but the problem is keeping your foot of the pedal.You probably could do 3in and a 2.5 or 3 out not sure. Also drop in K&N air filter will help mileage.

 

Don't expect to get any super gains in any of those catagories. I tend to disagree with most on here, as you could see with a quick search of older threads, but....

The flowmaster will sound great. The improved flow may give you another 1 MPG with a single application, but it really depends on your driving habits. The sound, oh the sound of flowmaster. Like music to the ears. You can see at http://www.flowmastermufflers.com/mufflers.html the difference in all their products, from the 40 series to the 70 series. Each one has its own characteristics for external and internal sound. I would say go for a 50 SUV or a 60 delta if you don't want it to loud. I use a pair of 40 series and they scream. If you truely want improved MPG and power, you'll need to create a true dual system with equalization (H or X pipe) and a pair of flowmaster mufflers. Yeah, it costs a bit more, but it will pay for itself in MPG improvement over the life of the truck. And, increase the size of your pipe. I use three inch, but you can use smaller.

Finally, prepare for the barage of "why use flowmaster when you can use magnaflow" responses (to which there is nothing wrong with, just prepare for them )

 

You honestly think that 3" true duals are the way to go to get the best performance? You really think that will net you enough increased fuel mileage to be of benefit?

I hate to be this way, but with each post you prove your stupidity. Good job.

 

If you read most of the posts on here, you would know that I recorded over 1.5 MPG gain after the exhaust was installed. If you can add, you would know that with a 30 gallon tank, you could add 45 miles with a 1.5 MPG increase. You could then figure at just 10MPG that would get you an average of 4.5 extra gallons out of the same tank. An extra 45 miles per tank, assuming 1 tank a week or 52 tanks a year, was 2340 miles. That would conserve 234 gallons, at $3 a gallon. Which, again being mathematically inclined would lead you to $702 in savings a year. Which in my case, paid for the exhaust and had money left over in less than a year. Of course, thats assuming 10MPG and not better. I was getting 11.6MPG before the blower, so you do the math.

And if you want to look like an ***, make some more assumptions

 

Did you read the original posters question? Since you obviously didn't and are just blindly recommending the crap you run for exhaust I'll help you.

"I'd love to get to hear some of that V8 sound without getting too loud."

"Will just a single exhaust flowmaster help with gas mileage and performance and give a good sound?"

"Also, what size in and out would I need for my truck?"

"I'm sure it would be nice to upgrade to dual exhaust, but I'm looking to go as cheap as possible right now."

You didn't answer ANY of his questions, and ignored the fact that he DOESN'T want to go true duals. I'll ask the same question of you again. Do you really think that 3" true duals will offer the best overall performance on an otherwise stock engine?

 

Line by line, READ

I said "Each one has its own characteristics for external and internal sound. I would say go for a 50 SUV or a 60 delta if you don't want it to loud"

I said "Don't expect to get any super gains in any of those catagories."

I said "And, increase the size of your pipe. I use three inch, but you can use smaller."

I said "If you truely want improved MPG and power, you'll need to create a true dual system with equalization (H or X pipe) and a pair of flowmaster mufflers. Yeah, it costs a bit more, but it will pay for itself in MPG improvement over the life of the truck. And, increase the size of your pipe."

Now, READ and you can see that I answered every single question he posed in my original post. You, are an idiot. You have no idea what you are talking about. You don't know anything about what I have. You are blindly calling what I run crap, with no knowledge of what I have setup. You are showing plain ignorance. The poster asked a question, to have everyone share their opinion of what he should do and share their experiences. I shared mine. It kinda goes back to the old saying, "opinions are like @$$holes, everyone has one, yours just stinks worse than the rest." So if you have nothing to add to helping this guy with his exhaust, why don't you go and find another topic to flame on

 

hwm3 needs hooked on phonics. can anybody help him?

 

 

huked on foniks wurkd 4 me!

 

Sorry. Your right. Flowmaster is the best. 3" true duals are the way to go to increase power and mileage. An exhaust system will pay for itself with increased MPG. Stainless steel is only for rich people. Magnaflow is for ricers.

Does that make you feel better little guy?

 

Whats a matter?? Get pissed off because you called me out on something that you obviously didn't read in the first place and I hammered it home for you? \

The point here is not to re-educate someone on what they like or don't like, but to provide others with details of experiences with products they are looking to buy. It is not my goal to have you roll over and say something, your play here is to give you say about what you use.

 

Have you tried and or compared the differences in true dual 2.5" or 3" in that same combination to show that the effects of nearly double the flow size will result in appreciable gains?

In effect, are you stating that a true dual 2.5" will not provide the benefit of the dual 3"? I'm jsut arguing the presence of diminishing results. Is 3" necessary? a single three inch pipe will support 400 bhp in street trim or 350 bhp in race trim (high compression/LT headers.) Several twin turbo applications I have build run 650-660rwhp through dual 3" with only a 10-12 rwhp sacrifice to maintain track sound levels.

 

I haven't had a lot of experience with it in the 5.4 motors, however I have in the 5.0.

In a 1989 5.0 that was upgraded to Cobra or better everything, I had two seperate exhausts. The first was a set of BBK shortie equal lengh headers with aftermarket 2.5 catless to flowmaster 40's. It sounded great, ran like a champ. When I got ready for more, I changed to bbk Full length 1 7/8 headers to 3 inch true dual with H pipe and flowmaster 40's. I dynoed +3 HP and I can't remember the tq. Its been some time back now.I had polished and ported heads, 24# injectors, bigger MAF, 292 .512 trick flow cam, TF lifters and springs, trick flow valvetrain all the way. The list goes on and on, I had like every single bolt on except for aluminum heads and a blower. (and I am not a big believer in NOS either)

Now, in a more or less stock 4.6 or 5.4 that has no intentions of a blower or bigger (better) heads down the road, I think the 2.5 will be fine, unless you are just really looking for some deeeeeep throaty sound, in which case you may loose a couple ponies

 

98Mani, you really need to lay off the Mustang comparisons to F-150. While true that they both use V8's and use the same block in later years, the goals of the owners are usually quite different. Also, you are one person. Statistically, your results and expereinces may or may not be what everyone else has.