HSD with tiptronic sequential manual shift mode?

old GS450h and current RX450h also have it, nobody talks about it

 

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The manual shifter may control that ratio, or it acts like a tiptronic on a CVT, and gives the illusion of gears.

These systems may make driving more fun, but with the computer ability to override driver input, they aren't give any noticable change in performance. And CVTs are in theory already using the most efficient gear ratio for getting demanded power to the wheels. I would think such a system would hurt economy. As a friend once said, "They're for when people are feeling frisky."

Note: I'm note talking about double clutch automatics. Just step transmissions and CVTs that the driver can interact with like a manual.

 

As Trollbait has explained, the HSD is fully computer controlled. Adding manual override control would be trivial, but not especially useful. Basically it would be a toy: fun to play with, but not an improvement.

Tom

 

It is a step backward to make it fun the old way. It is something to play with when you get tired of the jet-smooth acceleration.

 

Yup, a step backward. What gears? Shifting? Nonsense! But if you feel it necessary to play while you drive, go ahead. Don't let reality get in the way.

 

i have driven S-CVT in manual mode, and it works great... i have no idea how it work on Lexus Hybrids.

However, once again, in S-CVT, it works awesome and when you are trying to drive fast, it is much preferred to the auto mode. Before trying it out, i thought that simulated gears are non-sense, but not anymore

 

That observation does not apply to the HSD in the Prius. Being a fixed gear ratio electrical power split device there can be no advantage using manual shifting. It would only be for fun.

Tom

 

But are the simulated gears actually needed? I imagine a simple button for a sport mode would have given all the performance improvement one could ask for. Just switching to a different 'shift' map would also have been cheaper to implement without needing a different shifter or paddles, and the need to program steps into the map.

 

Some people like to be jerked around.

 

The RX450h has a "6speed" regen for hill decent. I made a post about it last winter I think. Never been used. You would have to be fully loaded with trailer on a long steep hill to need it from my experience.

 

If you want to nearly instantly adjust the power to the wheels, as in during max cornering, having a pseudo fixed gear ratio helps a lot. If you are doing serious performance driving on a twisty road you also want control over when a transmission shifts, so paddles or other means of controlling the transmission are highly desirable. None of that matters to well over 99% of Prius drivers, but as you get into vehicles of a more sporting nature that might actually do an occasional track day, it's important.

 

None of this applies to the Prius HSD. With the Prius, if you want to instantly adjust the power to the wheels, you move your foot on the accelerator pedal. Power with the Prius is adjusted by changing field currents, not shifting gears, manually or otherwise.

Tom

 

Don't need a track day, but I've got a lot of twisties on hill on the way to the lake. Having more control via a virtual transmission would be nice. That way I wouldn't have to hit the brakes nearly as much, and have a more positive feeling in turns. I had a manumatic before on a lex gs and this was the main time I shifted gears on that.

 

It takes over a full second for the full power to the wheels to be achieved when you mash the throttle to the floor in a Prius while you are going down the road at a steady speed. You don't have full power until the engine gets up to max revs and that takes over a second. Time it.

 

If those are priorities, then wouldn't you be better served with an actual standard transmission? Those with the desire can even rival a Prius' fuel economy rating in the real world. It had its flaws, but the original Insight with manual is still the absolute mpg champ.

 

No, for the price of some extra software and a couple of switches an automatic transmission can be tamed to behave the way you want it to behave as a performance transmission the small percentage of the I want a performance transmission and still be a normal full automatic the rest of the time.

 

there is an sport mode in S-CVT, but car does not know what you are doing or trying to do... it doesnt know where is the curve or where you need the power. when driving fast through bends, ability to downshift to increase engine drag is important.

it also makes it feel normal, which is very important for an regular CVT.

Again, I have never tried it for regular HSD or anything, but for Toyota's S-CVT, it changed my perception completely. I have no idea how it is implemented in CT200h in Japan, or RXh and GSh... but hopefully this new 2012 GS450h works as well as it does in Avensis I tried.