# 5.4 MPG improvement



## WOODY367 (Dec 19, 2002)

I have a 04 F250 with the 5.4 and 4.10 rear. It is getting about 96.5 mpg even on the highway. Has anyone done anything to improve the MPG besides keeping the engine turned off? cold air intake, programer?


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## cretebaby (Aug 23, 2008)

WOODY367;798460 said:


> I have a 04 F250 with the 5.4 and 4.10 rear. It is getting about 96.5 mpg even on the highway. Has anyone done anything to improve the MPG besides keeping the engine turned off? cold air intake, programer?


How much better do you want it?

I mean 96.5 mpg is pretty dang good already.:waving:


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## WOODY367 (Dec 19, 2002)

Anything is better. I kinda wish I went with the diesel but couldn't afford it at the time. Here the get better MPG.


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## AiRhed (Dec 27, 2007)

> Has anyone done anything to improve the MPG besides keeping the engine turned off? cold air intake, programer?


I've found that when I sell my Fords, and buy a dodge, my mileage increases instantly.....

For all seriousness though things that work include:

Get rid of every pound you don't NEED. Tape every body seam on your truck.(if you're nuts) Get more of a mileage based tune. Switch to synthetic, everywhere. Open up the air and the exhaust of the truck. With the ford, I would pay special mind to opening up the exhaust. Get a toneau cover or a topper. Use a fuel additive from Amsoil. Change your fuel filter. Swap in a rebuilt 24 valve 5.9L Cummins and enjoy unlimited pushing pleasure with 23mpg highway, without all the above...

Before I get totally flamed. I loved my 94 powerstroke, and I like the new trucks offered from Ford. They look great, just like all the other new trucks. But not a single company makes a truck worthy of its price tag. I have no brand loyalty anymore, I just run what I'm familiar with.


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## AiRhed (Dec 27, 2007)

Do you happen to be loosing/burning any coolant?


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## WOODY367 (Dec 19, 2002)

I have a Roll N Lock cover which is cloase when ever It can, no extra weigh in truck, run Mobil 1 oil and the fuel filter was change 3000 miles ago.I have been told the air intake and exhaust really don't help with the 5.4 and not worth the money. But thats why I am asking. What about a tuner?Truck has 52000 miles on it so I am going to change plugs soonseeing I have then and before the old ones get stuck in the heads.

As far as coolant all is good.


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## AiRhed (Dec 27, 2007)

Tell you what. I'll send you a pic Monday after work of what I'm talking about with the exhaust. You're definitely right about the air intake. As far as exhaust, I'm not talking about putting "pipes" on it. I'm talking about having a qualified exhaust shop or welder rework your y-pipe. There's a spot in the connection where pipe diameter is reduced to about an inch. Causing TONS of heat and terrible efficiency. Your mileage and especially your power will increase after getting rid of the little bugger.


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## WOODY367 (Dec 19, 2002)

Ok, look forward to it.


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## EaTmYtAiLpIpEs (Aug 23, 2007)

I cut my catalytic converter off because it was plugged and it gets 13-14 mpg with my 5.4.


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## WOODY367 (Dec 19, 2002)

EaTmYtAiLpIpEs;799040 said:


> I cut my catalytic converter off because it was plugged and it gets 13-14 mpg with my 5.4.


How do you pass emissions?


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## SuperdutyShane (Mar 6, 2009)

WOODY367;799062 said:


> How do you pass emissions?


You could take a code reader and clear the code before you go to get the sticker so it wont show up if you clear it. But it will soon come back but it wont matter for another year.


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## Milwaukee (Dec 28, 2007)

WOODY367;799062 said:


> How do you pass emissions?


put alcohol in gas tank so that should pass emission. Lot people do with old trucks with no emission stuff on it.

5.4L can get better than 5.8L It depend how heavy foot you have. I could get 23 mpg in 07 Lincoln Mark LT by stay at 63 mph with cruise control on.

If you still think you don't have heavy foot then go store get vacuum gauge and install on it. You will realized that you actual heavy on gas pedal.


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## AiRhed (Dec 27, 2007)

As promised....


































Don't mean to be harsh, but I doubt he cares much what someone else is getting with their 5.4 built by completely different people, on a different day, different year, with a different parts mix. HIS truck is getting 9mpg. And this is one of the major reasons why.


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## WOODY367 (Dec 19, 2002)

Thanks for the photos. I looked at the one on ebay.for $80. I think I might get one and try it out. To bad they don't make a bolt on. Thats alot of restriction there. Was chatting with a few guys today and said that he change it a seen a difference in power and mileage.


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## FordFisherman (Dec 5, 2007)

AiRhed;798540 said:


> Tell you what. I'll send you a pic Monday after work of what I'm talking about with the exhaust. You're definitely right about the air intake. As far as exhaust, I'm not talking about putting "pipes" on it. I'm talking about having a qualified exhaust shop or welder rework your y-pipe. There's a spot in the connection where pipe diameter is reduced to about an inch. Causing TONS of heat and terrible efficiency. Your mileage and especially your power will increase after getting rid of the little bugger.


Does this need to be custom fabbed or can you buy it off the shelf? Appreciate the info- never knew about the y pipe restriction


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## WOODY367 (Dec 19, 2002)

They are forsale on ebay and at www.spdperformance.com You have to cut the fanges off the factory Y pipe and weld in the new Y-pipe.


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## mvhauler (Jan 26, 2009)

AiRhed, I take it that your mileage has increased. Ponies also? Please elaborate. I'm already getting 12-13 on the highway. Thanks.


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## EaTmYtAiLpIpEs (Aug 23, 2007)

WOODY367;799062 said:


> How do you pass emissions?


my truck is over 8klb gvw. it doesnt need emissions only safety check.


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## AiRhed (Dec 27, 2007)

> AiRhed, I take it that your mileage has increased. Ponies also? Please elaborate. I'm already getting 12-13 on the highway. Thanks.


I'd be happy to elaborate. However I do not own a Ford with a 5.4. I had a Ford with a 7.3 Powerstroke, and I now have a dodge with the cummins. So I have no direct experience.

I snapped those pictures today at our local 4x4 custom shop. These guys are the do it right or not at all kind of shop. They have done custom Y-pipes on probably 70 or more superduty's with the 5.4L. From their experience the new pipe is an immediate seat of the pants improvement in power. I have no HP numbers to give you, just actual seat of the pants stuff. Which is honestly, better than just some numbers. He also has measured a significant decrease in exhaust temps, increase in exhaust flow, and some definite mileage benefits. From just the picture, it is blatantly obvious how inefficient that junction is, in my opinion, any improvement to that pipe should net some decent HP and MPG gains.

I hope this info has helped some of you guys?


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## mvhauler (Jan 26, 2009)

Thanks for the info. You are correct in saying there is an obvious restriction at the connection, am considering doing this and was looking for as much info as possible. Thanks again!


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## WOODY367 (Dec 19, 2002)

Thanks for all the help full info and photos. I just ordered it. Got nothing to loss for the price and everything you said makes sense. Thanks again.


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## AiRhed (Dec 27, 2007)

Anytime you guys. I'll say, if I start to get 9mpg in my Dodge this winter. I sure hope someone with a creative solution comes a long for me!


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## grec-o-face (Jul 7, 2009)

WOODY367;799559 said:


> Thanks for the photos. I looked at the one on ebay.for $80. I think I might get one and try it out. To bad they don't make a bolt on. Thats alot of restriction there. Was chatting with a few guys today and said that he change it a seen a difference in power and mileage.


I'm running the eBay unit on my V10 and it's a huge difference in MPG. I think I've gained 2-3 MPG. It also changes the sound of the truck - much better.

In all honesty though, I think this mod would work best WITH custom tuning. Anytime you open an exhaust & intake (especially on a newer "modular" ford) they tend to run leaner than normal. With a tune - it's all better.

Oh, and as far as the install of the new Y-pipe... a few hours, a sawzall, and a MIG welder is all you need.


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## mtchockey30 (Jun 10, 2009)

good info!


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## grec-o-face (Jul 7, 2009)

WOODY367;800080 said:


> Thanks for all the help full info and photos. I just ordered it. Got nothing to loss for the price and everything you said makes sense. Thanks again.


If it's the same guy I got mine from, SPD performance, expect a lengthy shipping time. Otherwise, it's good stuff.


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## WOODY367 (Dec 19, 2002)

grec-o-face;800241 said:


> If it's the same guy I got mine from, SPD performance, expect a lengthy shipping time. Otherwise, it's good stuff.


Yes thats who it is. I will see how long it take to get.Any suggestions on tuners?


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## grec-o-face (Jul 7, 2009)

WOODY367;800250 said:


> Yes thats who it is. I will see how long it take to get.Any suggestions on tuners?


I like SCT stuff and dyno tuning just depends on who you trust in your area.


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## suzuki0702 (Apr 6, 2008)

AiRhed;799690 said:


> I'd be happy to elaborate. However I do not own a Ford with a 5.4. I had a Ford with a 7.3 Powerstroke, and I now have a dodge with the cummins. So I have no direct experience.
> 
> I snapped those pictures today at our local 4x4 custom shop. These guys are the do it right or not at all kind of shop. They have done custom Y-pipes on probably 70 or more superduty's with the 5.4L. From their experience the new pipe is an immediate seat of the pants improvement in power. I have no HP numbers to give you, just actual seat of the pants stuff. Which is honestly, better than just some numbers. He also has measured a significant decrease in exhaust temps, increase in exhaust flow, and some definite mileage benefits. From just the picture, it is blatantly obvious how inefficient that junction is, in my opinion, any improvement to that pipe should net some decent HP and MPG gains.
> 
> I hope this info has helped some of you guys?


this is incorrect information. your driving a 8000lbs vehicle with 260hp. that restrictive pipe was designed for backpressure. this has topic has been beaten to death! i do own a 5.4l and drive it daily. #1 keep your rpms below 2500. #2 dont buy speedway gas. #3 dont buy into the tuner/exhaust is too restricted crap. im sure the engineers at ford designed that pipe for a reason, not so you the consumer would have to buy more fuel. i think ford is secretly partnered with fuel companies. tuner wont net u any better mileage, nor will that hunky dory pipe. get a k&n filter, that'll get your throttle response better. and if you really want to net a good change, u need a gear change. 4.10 or 4.30 ok im done now


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## grec-o-face (Jul 7, 2009)

I'm going to disagree. After building and racing several ford cars and trucks, I'm pretty familiar with the gains that tuning provides. I'm not trying to start any forum-wars, but my experiences have proven that simple open-loop/closed-loop on/off is good for power gains and MPG improvements.
The improved design Y-pipe certainly helps too. There are always ways to improve power over stock. Sh!t, Edlebrock, MAC, Flowmaster and many others have made businesses based on it.


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## AiRhed (Dec 27, 2007)

> this is incorrect information.


 Are you serious? You must be a highly experienced ASE Certified mechanic with 40 years or more under your belt. Because your going against what two ASE certified techs with a combined 80 years in auto's told me WORKS for these trucks. If I hadn't heard it from them, and believed it was FACT based on real world trial and error, I wouldn't of said it at all.



> im sure the engineers at ford designed that pipe for a reason


 I'm sure the Engineers at ford DID design that pipe like that for a reason. Like built in obsolescence. Backpressure is a BS excuse for the design of that pipe, BP can be handled further down the system within the muffler or in a smooth pipe diameter change. Not in some abrupt bottleneck like that. If I was building an exhaust system for a supermileage competition vehicle, and put a pipe like that on it, I'd be laughed out of the shop/competition. Fluid dynamics is a complicated and integral part of automotive exhaust system engineering, that pipe shows absolutely NO application of it.


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## swtiih (Nov 30, 2008)

Woody367

Aside from the differing opinions.
Let us other 5.4L owners know how this works out after you install.
I am getting about the same mpg.


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## WOODY367 (Dec 19, 2002)

Will do.Going to be busy the next few weeks so as soon as I have time to do it and test I will report back.


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## Sno What (Oct 23, 2006)

Well it may be off topic - but I had an 89 5.0L mustang. When I switched the factory headers out, some of the pipes were almost flattened. Why? Probably not from the engineers who designed it, but the guy on the assembly line that puts it together. Without smashing the pipe down, it would be hard for them to get an impact socket on it.


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## grec-o-face (Jul 7, 2009)

Sno What;802906 said:


> Well it may be off topic - but I had an 89 5.0L mustang. When I switched the factory headers out, some of the pipes were almost flattened. Why? Probably not from the engineers who designed it, but the guy on the assembly line that puts it together. Without smashing the pipe down, it would be hard for them to get an impact socket on it.


Actually that's how all of the old 'fox-bodied' 302 mustangs are. They all have those flattened areas. And of course, you replaced them with aftermarket headers that didn't have any flat spots.
Again, aftermarket parts are mainly designed to IMPROVE upon factory parts.
By the way "Sno What", I'm diggin' your name!! very cool!!


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