Gearing Automatics to get better FE

[MorningGaser]

Originally Posted by Bill in Houston

They (automatics) are sometimes rated better on the EPA test, but I don't think that it holds up in the real world. Over on a Honda Element group that I am in, every time that someone complains about their gas mileage, they are driving a automatic... That is anecdotal, I know.

I think you're right...with a manual one has more control over the shift points, and can do it better then any computer, to be sure, so it's easier to get high mpg with a manual of course...still, the AT's have come a long ways from the 1953 Oldsmobile FluidDrives......lol

I bike to work mostly, but on weekends, I use the car to get around all over...I mostly had manuals all my life (age 47) but these days I'd rather let the car do the shifting and even with that I get great mpg...

[SVOboy]

Originally Posted by MorningGaser

I think you're right...with a manual one has more control over the shift points, and can do it better then any computer, to be sure, so it's easier to get high mpg with a manual of course...still, the AT's have come a long ways from the 1953 Oldsmobile FluidDrives......lol

I bike to work mostly, but on weekends, I use the car to get around all over...I mostly had manuals all my life (age 47) but these days I'd rather let the car do the shifting and even with that I get great mpg...

CVT will soon, and I'm sure in nearly every case, replace the stick shift!

[Bill in Houston]

And it's also sort of a case of the automatics being tweaked to get good mileage in the EPA test, with less concern for real life.

I think that in the next ten years we will see huge amounts of progress in the efficiency of automatics.

[rh77]

Originally Posted by SVOboy

CVT will soon, and I'm sure in nearly every case, replace the stick shift!

True -- once a reliable design is forged (some have longevity issues at current).

I recall a car mag or show testing a CVT vs. Manual (Nissan Versa maybe ???) and the manual ended up with better FE. In this case, it took more energy to operate - even though it kept the engine in the most efficient range of load, RPM, etc. A regular auto wasn't available for comparison.

To be honest, the CVT is an entirely underwhelming experience to drive. Give it some throttle, and blah. Less feedback to the driver as is the case these days...

[GasSavers_bobski]

Originally Posted by rh77

To be honest, the CVT is an entirely underwhelming experience to drive.

Agreed.
I've driven my step father's '06 Civic hybrid a few times - Even in sport mode, the transmission takes forever to let the engine rev up to a speed where it's making a useful amount of power. I'll be more interested when they produce a version that, in response to throttle input, can go from 1 to 6k RPM in a second or two. As is, when I mash the pedal to (try to) accelerate quickly, I keep expecting it to downshift like a normal auto, bringing a boost in power. But no, the engine just drones away, ever so gradually gaining RPM while the car slowly glides up to speed.

[Bill in Houston]

They need to include some kind of "autostick" feature on the CVT, except make it like a continuous sliding switch instead of up/down shifts.

[slurp812]

Originally Posted by Red

I might increase demand, but how many people on the road know how to drive a stick?

I once drove an automatic car that was very similar to the stick shift car I owned at the time. I put it in first, then slammed on the brake to shift into second and nearly put myself through the windshield. So I tell people I dont know how to drive an automatic.

[GasSavers_bobski]

Originally Posted by Bill in Houston

They need to include some kind of "autostick" feature on the CVT, except make it like a continuous sliding switch instead of up/down shifts.

It's called the gas pedal.
But yeah, manual control separate from the throttle could be interesting. I would worry that a simple slider would be too easy to accidentally bump into a less than ideal setting, or that mounting it in a convenient location would require making it too small to adjust precisely. Using a set of up/down shift buttons like those in use now would probably be more practical. Just set them up so they lower or raise the gear ratio when you hold them down. Maybe make them pressure sensitive like the buttons on modern game console controllers... Press harder and the ratio changes faster.
Such discussion also begs the question: How useful would manual control of a CVT actually be? I suppose you could modulate engine torque output while keeping it at a fixed RPM, but how useful would that really be? I'm having a hard time thinking of a set of conditions where manual control would be advantagious when compared to computer control.

[Bill in Houston]

Originally Posted by bobski

I'm having a hard time thinking of a set of conditions where manual control would be advantagious when compared to computer control.

I dunno, bobski. You were the one complaining about the ratio taking too long to change. I thought that if you could control it yourself, like one does with a manual transmission, you might like it better. I think that I would. When you need to punch into a smal hole in traffic, you drop the ratio and crank the revs, wait for the hole, and then nail it. Vs the sloooowww agony you described...

[rh77]

I rented a Ford Fusion recently (review pending) and it had the annoying "Low" gear selector like most cars anymore, instead of "3, 2, 1". So, with the 5-speed auto, if you're cruising along at 40 and shift it into L for an extra boost (for example on steep hills or on gravel), it downshifts to 2nd and if you get too slow, it lurches into 1st at around 25 without warning. It's also weird from L to D from 2nd -- clunk, clunk, clunk and you're back into 5th. (no O/D on-off) Also the rolling shift to Neutral to try and coast resulted in a jarring disengagement vibration. Good grief.

RH77