Why don't ford, Chevy, or Dodge use the programming the aftermarket programmers use for better MPG?

I know about the idiot factor when the power is turned way up on a diesel programer but why don't the vehicle manufacters use mild tuning to provide better fuel economy. I had the edge on my 6.0L f250 and gained a few MPG but had to take it off for warranty reasons (in and out of the shop too many times).


I thought the driveability was way better with it on.Why don't ford, Chevy, or Dodge use the programming the aftermarket programmers use for better MPG?
actually the pcm programming is mainly done for EPA regulations. the pcm parameters need to be set at a ';safe'; compromise for power, economy, and durability. could the big 3 chane the injector pulse and spark timing to make it more efficent? sure, but what if that increased pollution? then the EPA will label the vehicle as a gross polluter and prohibit sales. dont even get me started on the state of california...my manufactuer has a fix for an intermittent stall at idle on an 05 vehicle, proved it works, yet cali refuses to allow the reporgram to be used...Why don't ford, Chevy, or Dodge use the programming the aftermarket programmers use for better MPG?
laws and regulations ,
They try to put it out not in too much favor of either way. They know people typically buy vehicles like that for their capabilities, people who actually use an F-250 for what it was intended, do not have them for the MPG, they have them because they need towing capability, and ';driveability'; or comfort are not high on their priority list.





If you like it, use it, but if it voids your warrant, then that's your choice, but the vehicle will come as evenly proportioned as they feel is fair to the entire customer base, not just the ones who buy an F-250 and worry about fuel economy, if you were that worried, you'd buy a Focus or a VW, or something similar.
Big Oil has too much influence on them. Better economy=less fuel purchased=less money for Big Oil.

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