I have a 1997 F250 with a 351w 5.8L. Im looking to get better gas mileage out of this good old truck. I keep up on the regular maintenance, and I realize it is shaped like a brick and not the most aerodynamic. But Im trying to do what I can. So far the only thing I have done (aftermarket) is a custom, true dual exhaust. opening the pipes to 2.5" all the way back. I was going to look into a K&N high flow intake next. But wanted to hear your thoughts, or suggestions of other ways to go. After the intake, i was also going to look into a computer programer/chip. Any thoughts and help would be appreciated. Thanks

 

Forget the K&N hot air intake,the filter box is NOT a bottleneck on these trucks, a set of headers will do more for you in power and economy..

 

What kind of MPG are you getting now?

 

65+ Vehicle modifications for better fuel economy - EcoModder.com

100+ Hypermiling / ecodriving tips & tactics for better mpg - EcoModder.com

 

Place an egg under the skinny pedal; don't break the egg.

 

the 5.8 did not get much better mpg than a 460 Weight of truck plus when ford first came out with fuel injection they said do'nt plan on getting great gas milage .the later 95 to 97 did get better ford used a different cam and heads on the 95 96 f150 and Broncos I;m not sure on the f250s I got a 95 f250 4x4 460 5spd stick and with all the mods I have made duel exhaust trottle body spacer and air intake the best I have ever gotten is 13.5 on the highway thats keeping it around 65 mph over that milage realy drops Just driving around I'd say about 10 mpg and it really don't make much difference how you drive it

 

Its a work truck does tow my bobcat on a car hauler trailor pretty good .the fact is pulling 8000 lbs does't really change the mpg that much 8 to 10

 

must say my v10 gets better mpg than the 460 15 mpg on long trips out west got to keep it around 70 after that mpg goes down

 

I got a v10 my buddy has a 3 valve 5.4 in a 06 superduty and he gets no better mpg than I do

 

If you can get 13 mpg with your truck thats about the best you can ask for

 

And the new 6.2 gas in the super duty they run great pull great but mpg about 14 tops plus the 2 plugs 2 coil packs per cyl

 

And the new Dodge hemi the same 2plugs per cyl .I got a brother in law with a 2008 dodge Hemi He gets 14 to 15 empty on the highway pulling a 16 ft 800 lbs boat and trailor 13.5mpg .I was with him a fact .In the hills the trans was always shifting down My 2003 v10 never shifts down with his boat on back

 

That really required 7 posts? So much of this is a big load of garbage and misinformation.

Besides the dual exhaust, the mods you listed on your truck didn't do anything to help you. If OP is getting 13, he can definitely do better. And if he's getting the MPG of a 460, he can certainly do better. You have no idea what you're talking about and there's no reason you needed to go on for 6 more posts of nonsense and illiterate babble.


OP, if you are getting 15MPG or so you are doing well.
There are a lot of posts on this site about getting better MPGs and improvements people have done for cheap. Do a little research on this site. Look up the "Six Liter Tune Up". You can bump your timing up from 10* BTDC to 12*. A set of headers will improve MPG and power. If you want to go a little more in depth on it, you can swap out the cam for a little more aggressive one.

The post FORDF250HDXLT made is also worth looking at.

The K&N "Cold" air intake is a waste of money on this application, as well as a programmer. Anything a programmer would do, you can do for free. They just bump the timing.

 

one simple thing that may help (especially if your like me and your foot has the tendency to drop the skinny pedal to the floor) is install a vac gauge (yes I know it doesn't do much) but it will help you keep the engine from excessive RPMs, also another simple mod that you can try is to take the accelerator pedal and put a spring thats a stronger one to give more resistance to the foot pushing down to make it a bit harder to keep the foot from pegging to the floor...