Quote:
Originally Posted by redlightningsvx
wouldn't keeping it in power mode most of the time hurt the tranny? hurt gas milage? or do any harmful things overall?
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Since we don't have any hard numbers concerning power mode and the 4eat, we have to rely on common sense to provide us with an educated guess.
The transmission is operating at a higher rotational speed more of the time in power mode. As others have said, at lower throttle points, the transmission shift points are just a little higher than they are with power mode off. Shifts are made proportionately higher the more the throttle is depressed, and it seems to follow a linear curve. with your foot halfway into the throttle, for instance, the 1-2 shift is done at 4000 rpm, the 2-3 is done at about the same. 3/4s of the way in shifts move to 5500 rpm.
With that said, our transmissions do not fail because of weight or power applied, they fail because heat breaks down gaskets and such in our trannys, and the resultant material clogs the fluid paths, causing further heat... ad nausium, until the transmission fails. With the transmission rotating at a higher speed, fluid is pumped through faster, and cooled faster. Also, at lower gears there is less rotational stress on components. (think of a high gear on your bicycle vs. a low one, which one do you think puts more stress on the chain/gears?)
This causes me to believe that power mode has either no impact on transmission life, or a positive effect.
As far a milage is concerned, I have noticed no drop in mileage at all. There is some voodoo math involved here to figure out which is more economical, as when the engine is spinning the transmission faster, less torque is required to achive the same speed, so engine load drops, but injection becomes more frequent. I don't think you will suffer a significant milage drop (except for the small fact the power mode makes it more fun to keep your right foot smashed against the firewall.)
These are just guesses, but I feel they have merit.
-Patrick