buddyIam wrote:
tystevens,
I suspect much of the downshifting is due to the auto transmission. I have had many vehicles, only one, a Pontiac in the 80's with a auto. All the downshifting is unnerving to me.
It isn't so much the downshifting that bothers me. It's the hunting. I've heard some vehicles give the driver the ability to control this hunting. Do any of your vehicle have the ability to do this.
It seems that it is only the big diesels that are going to stop the constant shifting. From watching the videos on big diesel testing It seems they do good job.
Well, sure, the downshifting is due to the engine needing to operate in its optimal range to make the power necessary. Personally, I don't think one is any better off 'forcing' an engine to lug and run below its optimal point, either from an engine life perspective or fuel economy. Sure, you can drop the Cummins in 6th and floor it, but that isn't going to help anything.
Anyway, to address your question, my F150 has the ability to control hunting in virtually every way. One can limit the upper gear selection (ie, allow it to operate in gears 1-3, or 1-4, etc.). The transmission will downshift per its programming, but will not upshift beyond the limited gear. The F150 has the ability also to 'lock in' to a specific gear, and the transmission will not be allowed to shift up or down (unless engine speed approaches stall, where it will downshift for you).
My GM only offers the first option -- limiting the top gear or gears available.
To tell the truth, however, I've been quite happy with the programming on both my Ford and GM 6 spds. In Tow-Haul, they do not 'hunt,' which I'd describe as shifting up and down in less than a couple minute period. Much better than older automatics I've driven -- my '05 Chevy would bounce endlessly between 3 and 4 unless I limited it.
And, like I mentioned in my prior post, my Ecoboost has the power to hold top gear in most freeway circumstances. It really doesn't downshift much at all -- I'd say it takes a 2% or more sustained grade to force a downshift to 5th when towing my 6500# trailer. Even then, it is only running about 2200 rpm until I get to the end of the grade. The only time it has shifted to 4th on the interstate is climbing the top end of Parleys' Canyon, which tops out over 7000 ft and is about 7% incline at the top according to my gps.
Sorry for the essay. In short, the 6 spd autos I've had in my last 3 trucks have been so good that I don't want another manual ever again (unless it is in a sports car).
