Lots of ppl are getting nice gains (~30 hp, ~30 lb*ft) by just flashing the ECU of their Evo IX. Why is it that the stock IX is tuned so conservatively? Is it some kind of compromise among emissions, reliability, gas mileage, etc? To reflash or not to reflash.... that's the question.

 

The answer is "Yes" to all of your list..

Gas mileage is probably the only exception as that is a closed loop and lead foot thing..

They have to accomodate gas of quite a few grades, and locations with varying altitudes and climates.. So the safe bet is to send the cars out with tunes that will tolerate these conditions.

 

What it comes down to is profit. Believe me they know how much power it can make. They tune is conservatively so that they last. Hence fewer dollars they pay out in warranties.

 

california

 

malibu jack nailed it

 

the EVO 8 factory tunes look worse