Tuner or Performance Chips - Do they work?

Basically NO. Intake and exhaust mods might help a little but you will never recover the cost of parts in fuel savings

Give this a try. If nobody there has an answer you don't need to know it.

http://www.ford-trucks.com/forums/forum28/

If these mods could really do something they'd already be on there.

2oldman wrote:
If these mods could really do something they'd already be on there.

Perfectly said. What manufacturer wouldn't want to boast the best mileage and the best power?

mike mck wrote:
Give this a try. If nobody there has an answer you don't need to know it.

http://www.ford-trucks.com/forums/forum28/

Tried the link but it didn't bring me to any specific forum, so I'm not sure where you stand on the question.
One thing to remember....no tuner can give you displacement, compression or greater flow of fuel mixture. Your vehicle is already programmed to give you the optimal fuel to air ratio. A tuner can do things like change shift points and timing, but it can't change the basics you need to produce more power, at least not on any kind of appreciable level.

The 460 is a very thirsty boy. 9 mpg in a 30' Class C is doing good. If you had a Class A it would only be 7 mpg.
Headers and exhaust will give some extra ponies but not change mpg much if any.
Don't worry - Be happy - Go campin'

jfkmk wrote:

2oldman wrote:
If these mods could really do something they'd already be on there.

Perfectly said. What manufacturer wouldn't want to boast the best mileage and the best power?

Sadly that's not the case.
Manufacturers save moeny anyplace they can - yes, at the price of better performance or efficiency. Because of that, performance is often improved by replacing stock parts with better designed and more expensive after market items.
The engineering staff of an aftermarket company like Edelbrock or Banks are given a much bigger budget than the oem will and they can sell the part form far more than an oem is willing to pay.
Finally, it comes down brain power. Some aftermarket companies simply have better engineers and/or they don't burden them with the limitations I've already stated.

Sorry, not going to happen.

If you could somehow make more airflow to give you more power you're going to use more fuel. The puter is going to keep air fuel mix a 14.7 to 1.

The only way to get better mileage is get your engine more efficient. Pretty tough to do. Raise the compression, it will get more efficient, but then you have to use better fuel. Jack the timing up it will get more efficient, but again you need to use better fuel.

Tuners do give you the option of putting the shift points where you want.

Want 2 to 3 MPG better? Get a diesel.

The manufacturer tunes the engine for the best power/mileage trade-off. If you tune for power or economy, you do it at the expense of the other. There is no magic chip that can do both.

My opinion is not much especially if increased fuel economy is your goal and your expectations are 2-3 MPG increase. As mentioned the timing and compression ratio are already maxxed for regular gasoline.

There are a couple scenarios for increased power. One is through improved airflow, generally at higher RPM. Exhaust modifications, intake modifications, camshafts. Nothing I can think of with these mods increase fuel economy. Most of these mods are way up in the power band and require revving engine high to get the benefit from them. Some are actually at the expense of low RPM power.

The other scenario is a chip which tunes the engine open loop under wide open throttle and significantly enriches the mixture at that time. You would have to confirm your stock engine is in closed loop at full throttle (14.7 to 1 mixture) to benefit from this mod. An open loop tuning could richen the mixture to 12.5 to 1 with attendant extra spark advance, and possibly premium fuel. This modification could produce noticeable torque increase across the band. It almost certainly would decrease fuel economy if full throttle were used often.

I personally have very strong doubt the aftermarket tuners/engineers are more capable than the factory. I also have strong doubt the modifications are run through the same proving cycle as the OEM do. IMO at your own risk.