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From: Mike Hunter on 25 Jun 2007 12:55
The two inputs to CC microprocessor are speed and RPMs. If you apply more
throttle to compensate for the loss of RPM, as you ascend a grade, the
tranny will not down shift as soon. The Japanese auto manufactures have a
tendency to spin their engines higher, to attain HP for advertising purpose.
The problem is that works fine on level ground where HP is doing the work
but spinning the engines separates the tongue curve and the HP curve.

Tongue is what gets you going and keep you going on a grade. The CC
processor allows for some variations in RPMs, to a point, then downshifts,
to get back nearer the torque curve, to pull the grade at the pre-set speed.

You can prove it to yourself if you hold the throttle at a specific level
and observe it downshift sooner than if you apply some throttle as you
approach the grade.

Nationally eight out of ten Camrys sold have the four, but around here
Toyota dealers stock and sell more V6 Camrys, since the four is a slug in
mountainous areas because of the poor torque at the proper RPM to stay in
higher gears, thus adversely effecting fuel economy.

mike


"C. E. White" <cewhite3(a)removemindspring.com> wrote in message
news:467fca44$1(a)kcnews01...
> Vehicle - 2007 RAV4 FWD (2WD) 4 cylinder, automatic.
> Problem - When the cruise control is used, the transmission
> downshifts/upshifts frequently when small inclines are encountered. If the
> cruise control is not used, the transmission does not shift in the same
> manner on the same inclines - in other words - if you maintain speed
> manually, the transmission does not hunt back and forth on minor inclines,
> but it does do this if the cruise control is used. Seems weird, but the
> behavior is so annoying my SO won't use the cruise control in many
> situations.
>
> Ed
>


From: tak on 25 Jun 2007 13:21

"C. E. White" <cewhite3(a)removemindspring.com> wrote in message
news:467fca44$1(a)kcnews01...
> Vehicle - 2007 RAV4 FWD (2WD) 4 cylinder, automatic.
> Problem - When the cruise control is used, the transmission
> downshifts/upshifts frequently when small inclines are encountered. If the
> cruise control is not used, the transmission does not shift in the same
> manner on the same inclines - in other words - if you maintain speed
> manually, the transmission does not hunt back and forth on minor inclines,
> but it does do this if the cruise control is used. Seems weird, but the
> behavior is so annoying my SO won't use the cruise control in many
> situations.
>
> Ed
I have a 2002 Rav4, does the same thing on even small grades if the rpm's
are 2800 or so, 3000 rpm's and it holds overdrive in most instances.


From: Ed White on 25 Jun 2007 14:45
On Jun 25, 1:21 pm, "tak" <taki...(a)frontiernet.net> wrote:
> "C. E. White" <cewhi...(a)removemindspring.com> wrote in messagenews:467fca44$1(a)kcnews01...> Vehicle - 2007 RAV4 FWD (2WD) 4 cylinder, automatic.
> > Problem - When the cruise control is used, the transmission
> > downshifts/upshifts frequently when small inclines are encountered. If the
> > cruise control is not used, the transmission does not shift in the same
> > manner on the same inclines - in other words - if you maintain speed
> > manually, the transmission does not hunt back and forth on minor inclines,
> > but it does do this if the cruise control is used. Seems weird, but the
> > behavior is so annoying my SO won't use the cruise control in many
> > situations.
>
> > Ed
>
> I have a 2002 Rav4, does the same thing on even small grades if the rpm's
> are 2800 or so, 3000 rpm's and it holds overdrive in most instances.


From: Ed White on 25 Jun 2007 14:48
On Jun 25, 1:21 pm, "tak" <taki...(a)frontiernet.net> wrote:
> "C. E. White" <cewhi...(a)removemindspring.com> wrote in messagenews:467fca44$1(a)kcnews01...> Vehicle - 2007 RAV4 FWD (2WD) 4 cylinder, automatic.
> > Problem - When the cruise control is used, the transmission
> > downshifts/upshifts frequently when small inclines are encountered. If the
> > cruise control is not used, the transmission does not shift in the same
> > manner on the same inclines - in other words - if you maintain speed
> > manually, the transmission does not hunt back and forth on minor inclines,
> > but it does do this if the cruise control is used. Seems weird, but the
> > behavior is so annoying my SO won't use the cruise control in many
> > situations.
>
> > Ed
>
> I have a 2002 Rav4, does the same thing on even small grades if the rpm's
> are 2800 or so, 3000 rpm's and it holds overdrive in most instances.

After reading your reply, I realized that I never really noticed much
of a problem with the cruise control forcing downshifts (it is her
compalinat) when I drive the RAV4 (mostly on trips down I-95). The big
difference between my driving and the SO's is speed - I usually drive
5 to 10 mph faster than she does on the open road. I guess I am
running the engine nearer the torque peak. On the other hand the SO,
always gets 1 to 3 mpg better than I do...

Ed

From: Hachiroku ハチロク on 25 Jun 2007 15:16
On Mon, 25 Jun 2007 11:48:23 -0700, Ed White wrote:

> The big difference
> between my driving and the SO's is speed - I usually drive 5 to 10 mph
> faster than she does on the open road.


Yup...that'll do it. Tell her to SPEED UP!!! ;)

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