Gearing Automatics to get better FE
 

Is it possible to change the gears to your automatic transmission to obtain a better MPG?

I know with the 03 Camrys there is a 4 speed automatic, with the 05, which is the same body style, they have the 5 speed automatics which gets better FC by an extra 2 MPG. So I was thinking. HOw hard is it to change the gears on your car to get better FC. Also would it be possible to have 5 speed automatic instead of a 4 speed automatic??

You should compare the transmissions and engines and things to see what the difference is, it might be that you can swap them, but it's hard to say with such a new car. I would trade it in for something stick, :)

Um... It's a PITA, but doable in a couple/few days. I want to say that the 5sp auto would bolt up, since it has the best OD ratio and in the past, Toyota has had manuals that couldbolt to both the four and six, but I'm not sure. It'll cost at least ~$500-1000, maybe more, and take many hours.

if it's rear wheel drive, change the differential
 

Easier to change the gear in that than fool with the tranny.

I think the general interest in FE is going to increase the demand for standard trans cars.

Might take a while before we see any effects of this in the marketplace (like higher prices or less availability of stick shift cars) because the reduced prices for sticks is kind of hard-coded into the "blue book" system.

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

They're going to want to learn to drive stick.
Some of them anyway.

Plenty "closet" stick drivers too, I'll bet.
Three drivers of four in our household can drive stick but are now driving auto.
# four thinks he can (22 yrs old), also on auto now, so that's 4 out of 4 really.
With mpg becoming more important I suspect at least 2-3 of the 4 will become stick drivers with our next cars.

Automatic (for now)
 

The 'Teg is an auto, which isn't by choice, but by default.

While the auto remains to survive with the EOC and traffic-light stop/start (about 20K miles so far), then into 'D', once it goes, a manual swap will be considered, but I'm not going to kill it intentionally...BUT

The auto allows a lower RPM at 55-60 mph than the manual version (with the TC lockup and final drive)....EVEN STILL

The same model in 5-speed form yields better overall mileage, and the ability to bump-start and no losses in swashbuckling through the ATF is another set of FE benefits...HOWEVER

Newer vehicles have an auto final drive that has a better EPA FE -- which I think the U.S. favors. People who actually prefer a true manual transmission is rare in the U.S. and Canada. So, automakers are making the autos more efficient (on paper).

I miss driving a standard-shift every day. The problem is that the TC engagement is intermittent with EOC (fuzzy logic / hill logic-control is confused by the EOC) and I drive quite a bit of highway speeds. When it goes, sign me up for a swap, but until then, I'm saving the $$$ on the mod.

RH77

I don't feel so bad having an AT Yaris...it is rated by the epa at 39 Hwy, and the manual is 40, and for city driving the rating is the same: 34 mpg...but with the help of a ScanGaugeII I routinely get 44 mpg out of my auto-tranny...granted I might get a tad more if I had a stick, but I doubt by much...with proper gas pedel control one can often "manually" shift, so this issue seems moot to me...these newer electronically controlled auto trannies are getting better and better, and with some cars they are rated even better then a manual version...

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...

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

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.

CVT Excitement
 

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. :thumbdown: Give it some throttle, and blah. Less feedback to the driver as is the case these days...

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.

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.

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. :D

It's called the gas pedal. :D
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.

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...

just rent me a manual
 

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

Any word on whether the semi-auto feature helps with FE at all? For example, we have an Acura and it has a semi-auto feature.

M