I have a 05 250 with the 3v 5.4 and I'd like to get some more power out of it and hopefully a little better fuel mileage. Right now I get around 11 MPG running around the country and like 13.5 MPG on the highway. What kind of gains can I expect???

 

Never expect MPG gains from ANY tuner. You will get more power and MAY see an MPG increase, but NEVER expect it. You will only be disappointed.

The power on the other hand...

 

What he said. At cruise, the system is in full closed loop operation - the amount of fuel being added is constantly being adjusted based what the 02 sensor sees.

It is possible to get a touch better if you run a higher octane tune as you can get more advance, but maybe 1/2 to 1 mpg at best? And that is very hard to achieve as it is so hard to NOT use the newfound power....

The big changes are in torque, HP, and transmission behavior.

 

Think of it this way, no change in MPG but a big change in efficiency. What's the difference you ask? More power with the same amount of fuel per mile, and if you're lucky, less fuel per mile.

 

With great power comes great responsibility.

It's easy to let your foot get heavy when you got the get up and go, I sure do notice more of that with my 6.8 tune, but that doesn't do much for the bottom line on MPG.

But when it runs better and shifts better you don't have to step on it so much to get it moving. That's where I see the most MPG gains.

 

Yeah I understand what you're sayin. I was just hopin to see some sort of MPG gain, just to help cover the cost of the tuner and make it even a little bit easier on the wallet. Every little bit counts nowadays.

 

There is an economy tune. I havent tried it yet. One would think with the title of economy it would be economical. Not sure. Email Mike and you will have an answer very shortly. He's on top of it dude.

 

I used the economy tune for my 7.3 and did not notice any difference maybe tad depending on seasonal fuel. My original thoughts were yep got better mpg but went up from 40 to 60 to 80 hp tune and only the grin factor improved..... still getting 17 to 18.5 on occasion.....

 

I gained 1 mpg maybe 1.5 at first
but the gain is lost after driving habits change

 

Not enough to pay for the tuner.....

but wait - I paid roughly $400 for mine and after selling the Ex sold it for $275, so $125 for 7 or more years of use.... chump change for the grins and mpgs !!!

 

Now I've heard before that some economy tunes made a vehicle feel doggish and not have as much power, did you notice this with the economy tune?

I will talk to Mike and see what he has to say, thanks guys.

 

On a gas powered SD do not expect any mpg at least on 87 octane fuel. I didn't buy a tuner for gas mileage.

 

nope discovered throttled response is snappy and it leads to lead-foot-itis a common ailment among oil burners with itchy feet..

 

i think you should be happy with the mileage u get. my 08 5.4 gets 11mpg on the city or highway so getting 12.5 or 13.5 or whatever u said is pretty good.