mike- shift characteristic ?
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Senior Member
Joined: Jul 2003
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From: irwin,pa
Mr T
at about 50 miles noticed the shifts were getting firmer- but not like the 87 mpg tune- does it have to do with it being an mpg tune?also should i load the 93 performance tune to see how it shifts compared to the 87 tune? thanks-phil
Hope none of them were you...
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Joined: Mar 1998
Posts: 13,385
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From: Virginia
Hi Phil,
The MPG tune will shift differently - absolutely. Sooner, and the TQ locks up sooner as well, and it won't downshift as easily, etc. That's what an "MPG" tune is supposed to do (among other things), as for best mpg you want to run as few rpms as possible.
But don't forget about the very important aspect of every time you change programs, you're wiping out all the previous adaptive strategy adjustments to both engine AND transmission, and the system has to go back thru the relearn cycle again too, which further affects tranny shifting - this is why the shifting changed after you accumulated some miles. This is mentioned in most vehicle owners manuals in regard to disconnecting the battery, because that also clears the PCM of adaptive strategy adjustments & puts you back thru the relearn cycle again - so the tranny can shift either softer or harder than "normal" until it gets thru relearn, in anywhere from 50-500 miles or so.
All in all, you are going to see a bit more noticeable differences in shift points & shift characteristics between your different programs in this van as compared to what you saw with the program combination in your LGA2-code '03 F-150 - in addition to going back thru relearn again each time you change programs which makes the tranny relearn it's shifting characteristics again.
Talk to you soon,
The MPG tune will shift differently - absolutely. Sooner, and the TQ locks up sooner as well, and it won't downshift as easily, etc. That's what an "MPG" tune is supposed to do (among other things), as for best mpg you want to run as few rpms as possible.
But don't forget about the very important aspect of every time you change programs, you're wiping out all the previous adaptive strategy adjustments to both engine AND transmission, and the system has to go back thru the relearn cycle again too, which further affects tranny shifting - this is why the shifting changed after you accumulated some miles. This is mentioned in most vehicle owners manuals in regard to disconnecting the battery, because that also clears the PCM of adaptive strategy adjustments & puts you back thru the relearn cycle again - so the tranny can shift either softer or harder than "normal" until it gets thru relearn, in anywhere from 50-500 miles or so.
All in all, you are going to see a bit more noticeable differences in shift points & shift characteristics between your different programs in this van as compared to what you saw with the program combination in your LGA2-code '03 F-150 - in addition to going back thru relearn again each time you change programs which makes the tranny relearn it's shifting characteristics again.
Talk to you soon,
