Any one have any mods they have done to increase MPG. I know there are thousands on the internet but do they actually work?

 

Switching to 4.10 gears from 3.55 gained me about 2-3 mpg city and 1-1.5 highway. But that's with a tuner to correct the speedo. But I was running a performance street tune and not an economy tune so I'd imagine that with an economy tune I might have gained another mpg or two.

That's really the only one that worked for me.

 

So what are you getting MPG wise ?

Is that w/factory size tires?

 

The best mods where you can net a little bit, = E-fans, intake and exhaust.

E-fans would be the best. Intake exhaust work together , exhaust has to configured correctly. These are just small gains.

What's best is keeping you maintenance up to par, - MAF, O2's, plugs, coils...It takes quite a bit more than just one thing. That's just to keep mileage at what it should be. Aftermarket helps very little.

It's a truck, so it's not going to be great.

 

The best I ever got was a near factory rated 16.9 mix city/Hwy ith my 4x4.

Maybe with Electric Fans, lighter tires and a custom Tune you could get better but there's no special product that's going to give you a constant measurable increase.

With the 3 things I listed, you'll only be on the high side of factory MPG; which is better than the low side.

It's an old truck heavy truck. There's not much more you can do.

 

new ones Are heavier though.

 

Engine technology has taken leaps and bounds since then.

 

Some may "work", but not make a difference.

The cost of any "improvement" will take a very long time to recoup (if ever).
Improving 2 mpg (say 13 mpg to 15 mpg) will save you ~$300 a year (if you drive 15,000 miles with gas @ $2/gallon). After 5 years, your up to $1,500 saved. (a website to figure it out easily)
Lighter tires, tuner, gearing, electric fan, intake/exhaust will cost you at least that, all for minimal gains.
5 years to just break even. Will you still even have the truck in 5 years?
I have yet to see anyone willing to go to a smaller, lighter tire. Everyone seems to want bigger, heavier tires.

The best mileage improvements are free. How you drive will make more of a difference than any add on. Smooth acceleration, nice easy stops, reduced idling, driving the speed limit (or a little below), keeping RPM's low (at least under 2000), reducing weight (empty the bed, don't carry 50 lbs of chain on the front of the truck, stick with stock bumpers), keeping your tires properly inflated, proper routine maintenance together make a huge difference.
Your driving type and location makes a huge difference too (local short trips, all highway, hills, mountains, speed limits etc). My mileage where I am and how I drive is not a comparison of what your mileage will be for you. You can easily see my long term MPG in my signature, but tells you nothing about how I got there, and can't be used for a comparison where you should be.

All that being said, these engines were designed when gas was less than $1 a gallon and nobody cared about fuel mileage for a truck. It is big and heavy and meant to haul stuff, not to get 20 mpg (although the original EPA estimates for the F150 with a 2wd 4.2 manual was 15 city/17 combined/19 highway (source))

So basically, don't drive a truck to worry about MPG. Sure if it goes from 14 mpg to 8 mpg with no changes, then complain, but getting 11-15 mpg is what you can expect from these, with some occasionally getting better for a variety of reasons, but they are not the norm.

 

They are also tuned like Wet dogs from the factory, have better fuel management designs and higher speed transmissions. They are more efficient as a complete package.

 

The only exhaust setup that I noticed a change On was my new single tailpipe. Gained an avg 1.0 mpg across the range