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I'm not exactly sure what's going on. I've had my TCH for just about a month now, and I've put 3,000 miles on it (mainly from two long road trips, LA-SFO-LA and LA-Vegas-LA). Up till a couple of days ago, I averaged 42-43mpg on my daily commute. I'm not a committed hypermiler, but I do P&G when I can.

When I came back from Vegas last weekend, however, I found that for some inexplicable reason, my Camry just would not shut off the ICE when I drove my daily commute. Even when traffic on the freeway is at a trickle, going at 25mph, the ICE would still be running and my MPG meter swaying back and forth whenever I inched forward. It would only shut off if I accelerated past 35mph, but for some segments of my commute that is too fast and I would have to apply the brakes immediately afterwards. Only at the end of my commute would the ICE begin to act normally.

I used to get 42-43mpg a day, but now I'm barely averaging 38mpg a day and I have no reasonable explanation why! :mad:

Has anyone noticed this kind of behavior in their Toyota/Toyota-based hybrids before?

are you using the AC more than usual? Is the battery charge at low? - those would be my first two guesses ..

Igor

I thought that might be the case, too, but no. I keep my AC at 75 or turn it off entirely, and although I do sometimes run down the charge, most of the time it's at four bars (half charge) or five bars.

Even when traffic on the freeway is at a trickle, going at 25mph, the ICE would still be running and my MPG meter swaying back and forth whenever I inched forward. It would only shut off if I accelerated past 35mph, but for some segments of my commute that is too fast and I would have to apply the brakes immediately afterwards. Only at the end of my commute would the ICE begin to act normally.


If the TCH control algorithms are anything like those of the Prius, that sounds normal for what we call "Stage 3" operation. The deal is that at first you have to be going above 35mph for the engine to shut off while driving. I don't know why they did this, but it is one of the most common annoyances amongst Prius drivers. In order to get beyond this, you must come to a complete stop with the engine idling and wait for it to shut down (usually 5-10 seconds.) At this point the car transitions to "Stage 4" operation during which the ICE will shut down below 35mph.

If you are in true stop & go driving or driving with a lot of lights, it usually doesn't take long for the car to find an opportunity to make the transition. My bet is that you just haven't seen this before because you spent so much time on the open road rather than driving at low speed. If you can learn to work with the system's quirks you should get your FE back and then some.

Tim is right, often on the freeway the ICE shuts off while coasting down past 35, and you never reach stage 4. A useful tip is when you think traffic will be stopped (or going under 5mph) for about 10 seconds and the ICE is off, tap the gas while your foot is on the brake. That will start the ICE. If you are in stage 4, the ICE will shut back off in about 2 seconds. If it runs for 7 to 10 seconds and then shuts off, you were in stage 3, and now are in stage 4.

Oh, so if I don't come to a complete stop at all during my trip, my car will never transition into stage 4?

I was aware of the stages before, but I thought it was dependent entirely on engine temperature.

Well, now I know....

....and knowing is half the battle! (I'm sorry, please don't ban me. :p)

This is one of the things frequently discussed when people ask
"okay, so what's the benefit of an EV switch?" ... one HUGE
benefit is that you can override this brain-dead stage 3 behavior
until it's bloody good and convenient to do the stage-4 dance.
In the meantime you have to play the EV switch along with the
go-pedal to simulate the same effects at under 35 mph.
.
Gotta wonder if the TCH has an equivalent missing ECU pin...
do they sell them in JP/EU at all, or is that a US thing?
.
_H*

That's actually another question I had: where it was possible to get an EV button in a Camry Hybrid.

I have yet to hear of a EV button for the TCH. I think the odds are good that it's possible given that the Prius can do it and the '08 HiHy has an OEM button. Somebody needs to do a comparison between Prius and TCH systems.

That's why I ask about europe and japan. The prius switch
contact was determined by looking at those cars and comparing.
.
I think the hihy and camry ECU sets are completely different,
as the prius is different from both of those. In fact the
Hihy merges the engine and hybrid ECUs into one box, since
they need to be so tightly coupled anyways.
.
_H*

That's why I ask about europe and japan. The prius switch
contact was determined by looking at those cars and comparing.
.
I think the hihy and camry ECU sets are completely different,
as the prius is different from both of those. In fact the
Hihy merges the engine and hybrid ECUs into one box, since
they need to be so tightly coupled anyways.
.
_H*

The TCH is only sold in the US. But Japan only Estima Hybrid, Alphard Hybrid etc. come with EV switch.

Andrew