"Doug Kanter" wrote in
:

"Jim Yanik" . wrote in message
.. .
"Doug Kanter" wrote in
:

"Jim Yanik" . wrote in message
.. .


Auto makers have to engineer their electronic engine controls to
insure proper performance under a WIDE variety of operating
conditions and weather.

That's true of any car, and means nothing with regard to SUVs or any
other single category of car. If Ford wanted to make an Explorer
shift like a Crown Victoria, they could do it for peanuts.




I don't understand what you're driving at here.
What difference is there in the way each vehicle shifts,and how is
that meaningful?

Certainly the mass of a vehicle matters in shifting "feel".

To get the best gas mileage, the rule of thumb is to get OUT of the
lower gears as quickly as possible. To use an extreme example, this is
why "jackrabbit starts" burn more gas - you're in first or second for
a longer period of time than if you started more gradually.

Based on my experience with 4 trucks (mine, and the 3 I test drove),
they're designed to remain in 1st or 2nd somewhat longer than a sedan
with similar size & motor. In other words, to get up to 55mph from an
entrance ramp, I know how quickly it happened with normal cars I've
driven, compared to the trucks. This is not a defect or a bad design,
mind you. It's logical for a vehicle that's hauling a lot of weight.
You need the torque of the lower gears to get started. Granted, you
need some more just because of the weight of the vehicle itself. But
still, I believe the difference is a bit excessive.

Someone will say that you can control this behavior with your foot (in
an automatic), and that's true. But, if you do, there are plenty of
situations where you're going to get onto the highway doing 43 mph
like an old fart, rather than blending in safely at the prevailing
speed. In other words, in order to achieve the same acceleration you
had with the sedan, you HAVE to let the truck stay longer in the lower
gears.

At the other end of the spectrum, some trucks will downshift out of
overdrive when you try make even a slight upward speed adjustment.
They've certainly got big enough engines to not need to do this, but
again, the assumption in the design is that you're hauling something
heavy, so you need the extra kick.

The solution already exists: Buttons to change the shifting pattern.
Years ago, some Hondas had (and may still have) a button that I think
they labeled "Sport". My truck has a button that changes the pattern
to one that makes for easier towing on hills, providing even higher
shift points than it already has. Why not provide all SUVs with a
button that toggles between "shift like a car" and "shift like you're
hauling bricks and a boat". Make one mode or the other the default,
and make that easily programmable by the consumer. Educate them at
delivery. You know as well as I do that there are people who never
notice or use features. Have the salesperson ask them one question,
ask them if they have a preference, and if not, send the car out of
the showroom set to "Car".




Such a feature costs money to design and install.
The tranny controller must have the extra memory space for the additional
programming,and two programs must be created.Then each program has to fit
the government's EPA testing.

TANSTAAFL.

--
Jim Yanik
jyanik
at
kua.net