I'm curious to see what's happened to your gas mileage after installing the custom tune. My brother just installed the performance tune on his '98 F-150, and he said his gas mileage went up. He's looking forward to seeing what happens when he loads the ecconomy tune.

Has anyone with an '04 /'05 had this same result. I use my truck as a daily driver and have a 43 mile one way commutte. Fuel ecconomy is something I have to think about at over $2.00 a gallon.

TIA for your inputs. By the way, I have a 5.4 4x2 with 3.73 gears.

 

Search. Mine stayed the same, 'cept for the times I mash my foot into the floor to roast them... which is often. So, overall my MPGs have declined thanks to the tuner.

 

Lol dzervit loves telling everyone to search....then he answers your question so you don't have to search...it's great. I'm curious about the correct answer too though. If a tune gives more power through a richer A/F ratio, then the mileage will be less. However, I'm ignorant on this topic, so I will wait for someone to tell me I'm wrong and why I'm wrong!

 

Search and you'll get the whole story, not just my lame-o answer. If your driving style remains the same post-tune then in theory you should achieve more MPGs... a few folks even testify this is in fact the case.

 

You're wrong. You acheive power by leaning out the a/f mixture. It makes it burn hotter and allows you to run more timing.

 

wrong

"In short, "Closed Loop" fuel control operation is when the PCM is using the feedback from the oxygen sensors to constantly adjust the air fuel ratio to a 14.64:1 A/F ratio. You're stuck at "stoich" A/F, thus there isn't much spark advance that can be tolerated before the motor knocks, so the engine doesn't make maximum power - as is appropriate, as this is basically it's "cruise" mode, for lack of a better term - for just enough power to cruise and get it's best fuel mileage.

Open Loop fuel control operation is when the engine makes it's *real* power - in this mode, the PCM ignores the feedback from the oxygen sensors and no longer forces the engine to run a 14.64:1 A/F ratio - instead, it uses the signal coming in from the MAF meter or MAS to determine how much fuel and timing to put into the engine, based on hand-coded values in lookup tables that are based primarily on load, and the result is richer A/F ratios and that makes the engine able to tolerate more spark advance" a TP quote

 

Nice tech posting, jpdadeo! That's clear writin'

To others; Note the important part for more power is advancing the spark.
Temp of burn is not too important.


Fun is running too late engine timing, and having it burn in your exhaust manifolds.
Big problem when electronic engine controls first started. Cool to raise the hood and see exhaust manifolds glowing cherry red... Unless they're your exhaust manifolds


Chris (say, does anyone remember what this thread was supposed to be about? I don't.)

 

Ok so i'm running with a Diablo Sport programmer with a custom tune and from what you guys are saying is i need a leaner mix, a more advanced spark, and to increase the timing to get the most out of my little 4.6?

I should also add that i have and Airaid cold air intake and a throttle body spacer with flowmasters. The thing i'm most worried about is burning my engine. If there's a good chance that i'm going to blow something, please warn me!

 

Main thing to worry about is too advanced timing for the fuel. That leads to ping, which leads to detonation. Ping is fuel igniting as the piston comes up, hammering the top of the aluminum piston. Correct, ping, detonation, is just the difference in height of the piston at the time the spark kernel ignites.

So listen for ping.
If you hear it, usually at half throttle up a hill will provoke it if you are too advanced. Try it with engine warm. It can sound like a rattle, a mild roar, even a high pitched noise from under the hood.
Ping = Bad.
If the mix is too lean you may get a cel warning light. Leaning the mix is not going to help your performance. Richer makes more horsepower. Leaning it saves gas. Lean makes the engine hotter, thus increasing the likelihood of ping...

If you want to be safe, watch for ping, and don't over lean the mix.
Chris

 

Hey Mart Man that's my friggin truck xcept mines a crew cab! I got Roush wheels too.

Got one question for ya. Did the 2" drop shackles help the look in the rear end? I know that mine looks like it is kinda sitting about 2" too high.

You suggest getting the drop shackes put on?

P.S. Best looking ride on f150online IMHO.

Also, I got the Troyer XCal2. My gas mileage didn't go up. But that was only cause I like mashing the peddle a tad bit harder.

 

Mine stayed the same unfortunatly. Actually went down about .5 mpg with the 92 octane perf tune.