Hey guys, a rookie looking for some advice and this seems to be the best place for it. I went thru a lot of the threads before figuring out what I wanted to do to my 2001 F150 SuperCrew Lariat w/5.4L that I purchased about 6 weeks ago. I decided to add each piece and check performance, i.e. gas mileage, before adding another. First tank I got about 16 mpg running stock. This is all commuter mileage. Then I added an AirForce 1 and got about 17.3 mpg. Power plus economy which is my aim. Then I had the stock muffler cut out and a Magnaflow put in. Kept it SISO with the stock pipes and dropped it over the axle. I'm not a tailpipe fan. I love the sound and the engine seems to run smoother. However, my mileage has tapered off. In three tanks since, I'm only getting about 16. Back to square one. I drive consistent and have used Shell or Chevron but am now going with 76. Any suggestions? I thought my mileage would have gone up slightly with the Magnaflow. My next step is getting an Xcaliber but I'd like this solved before going further. Could my engine be running richer because of the pressure change so I definitely need to have the computer reprogrammed? Any help is appreciated. Thanks.

 

Don't take this the wrong way but, don't buy mods looking for better mileage. A lot of these mods claim better mileage and alot of people using these mods CLAIM they have experienced better mileage. There's also alot of people using these mods that experience no improvement in mileage or, worse yet, a decrease in mileage. You want better mileage, buy a car.

 

Welcome Ray,
This is an opinion, so don't take it as gospel. Either the exhaust work you did slowed the exhaust gas velocity enough to cause the mileage as well as mid range power loss, or maybe with the sweet sounding exhaust, you are driving a little more agressive. I had some exhaust work done on my truck, and the first time around, I lost some power and about 1.5 MPG. The second time around,I regained the economy and power...Kevin

 

My best results have been from exemplary maintenance, synthetic lubes, weight and/or resistance reduction, underdrive pulleys, and electric fans. Cost effectiveness is questionable at best.

 

Thanks guys. True, if I wanted superior economy I would drive a hybrid. But I cant afford a stable of cars and my truck serves many functions, i.e., commuting, camping, hauling. And I realize you cant believe everything you read/hear. Thats why I'm on this site. I'm just trying to get the most power and hopefully economy for the buck without getting too crazy. I just figured the Magnaflow would help. Haven't noticed any loss of power at any point in the range. It cruises easy at 1850 rpm @ 65 mph and 1925 rpm @ 70 mph so I know it not working hard. Like I was wondering, would an Xcaliber help out and should it be customized by Troyer? Again any suggestions would be appreciated. Thanks again.

 

This is my first post so Hi everyone.

I have been reading through quite a bit of forums regarding mods which yield the best over all performance for a reasonble amount of moola. In my opinion there are three mods which will offer the best performance/mileage benefits.

1. Exhaust
2. Underdriver Pulleys
3. Electric Fans

Other mods would include.

1. SSD cold air intake
2. Diablosport tuner
3. Headers
4. MAC or BBK 75mm throttle body.

Things to deffinatley stay away from.

1. The Tornando
2. Throttle body spacers.
3 Electric Turbo.

This is only my opinion after reading through multiple forums.

 

throt/spacers ? why even like a poweraid spacer hummmm inform me thanks M.W.

 

Yeah, like the Poweraid.

I have not personally installed one but I have read many a post where there was no power gain nor was there an increase of mileage. Plus you get that whistling noise.

 

Throttle body spacers may help older engines, the ones with the injecters in the throttle body, like a carb. I installed one on an older truck that I owned, and it seemed to help a little on low end power, but did nothing noticable for gas mileage. It seems to me that on engines that have an individual injector at each cylinder, these things are a complete waste of money, unless you don't mind dropping 75-100 bucks to make your engine whistle.

 

I got a t-body spacer for less than $30, so I figured it was worth a shot.

Turns out, I should have spent it on... dinner... anything else.

It was fun to put in, but hasn't done a damn thing, at least than I can tell from the butt-dyno.