Why CVT?

Try launch mode? Power button.

Seriously, the v launches and keeps on going to cruise speed with no drama.

 

I think that is more a problem of the engine size and power than it is a transmission problem.

 

It gets far more than that. Otherwise, you would be able to point to a car of similar size and weight with mpg that close.

Many folks who have driven only cars made during or after the horsepower wars of the 1990s are unfamiliar with the feel of common low powered econocars of the preceding generation. But for many of us accustomed to those 70s and 80s ecoboxes, the Prius can still feel peppy.

It is the engine size, not the CVT, that is getting you.

 

Don't forget that the "CVT" in the Prius is something completely unlike any other CVT you've ever heard of - the only thing it has in common with anything else called a CVT is the lack of fixed ratios. The transmission in the Prius "transmits" by computer-timed gating of electric pulses between two motor-generators and a battery, and that is the Toyota Hybrid System (or Hybrid Synergy Drive for newcomers). No Prius CVT => no Prius.

There are a lot of resources online where you can find an overview of how it works. I think you'd be interested.

-Chap

 

Your engine only runs at a few fixed speeds so the cvt and it's controls have to provide the variable speed component. In addition, it provides a high overdrive ratio when the car can take it. The CVT and the car's ultra reliable but complex control strategy is what won Toyota their patents.

 

I've come to enjoy the characteristics of the CVT, very smooth and uneventful. As far as "get up and go," My Prius has caught several other drivers off guard who thought they were going to leave me in their dust from a light.

 

try driving a volt. it's full of clutches, and has a completely different feel. unfortunately, they can't seem to make it work in a prius size car.

 

As Chapman said before, your cvt is completely different than the conventional belt and variable pulleys type of cvt. Yours is made from a planetary drive. It has the possibility to vary as needed the speed of the three elements of the system; the internal combustion engine and both electrical motors/generators. From an engineering point of vue, this design is awesome cause it is mechanically simple and as few moving parts. It means less friction, cheaper production cost, better efficiency and less parts to break or wear. I am really not sold to the new 8 , 9 or 10 speed transmission some manufacturers are selling now. Why such complex transmissions when you can get an infinity of ratios with a cvt? Another big advantage of the system is that it transfer to the wheels the power needed to rotate MG1 when it act as a generator. On a conventional car, the alternator takes power from the ice. The prius' MG1 play as a big alternator when the ice is working but his friction help to propel the car instead of being lost energy. Also, the three elements are countinuously variable so it lets all the versatility to the software to choose the speed of MG1, MG2 and ICE. This cvt is what attracted me to hybrid cars. When I saw it for the first time, I admit i felt jealous of not being the one who invented it, but the initial patent is 100 years old! The hybrid synergy drive have been invented at a time when no one as the technology to control it.

 

For some additional numbers for OP, the special CVT could allow the engine to drop to 0 rpm when gliding conditions are favorable. But to protect a certain CVT component from overspin, the computers set it to a minimum rpm at highway speeds, specifically 992 rpm in the GenIII Liftback above 46 mph. Other models have somewhat different limit setpoints.

Absent this overspin condition on one component (MG1), the Toyota 'CVT' can produce 'transmission' gear ratios over the full span from Zero to Infinity (or 'undefined' for mathematical purists). And it does so without any mechanical gear changes or adjustment, just changes to electric motor/generator speeds.

 

The Gen 2 (and Gen 1) CVT is slightly simpler than the Gen3 (he has a video on Gen 3 when you feel you have mastered Gen 2) so it is the version to study first.

It is unlike any thing I had seen before. From the standpoint of Motor/Generator 2, the Prius has a 1 speed transmission. D rotates M/G2 one way, R just rotates it the other way, N just does not power M/G2 (or M/G1) at all. P inserts a pawl to prevent M/2 from rotating at all. Simple mechanically, but I suspect the software is complex..

 

When you think about the Prius it is the ONLY car you can't abuse! The ECU and other computers just won't let you. It totally controls what happens and keeps everything in control. Besides I like the fuel economy the best.

 

I *love* to know every detail about how the Prius works, and am really enjoying it (and getting amazing mileage). So I love each of the posts in this thread (and the people posting them, in a technical way) with a passion


That said, I think the original poster just wants to enjoy his car and feel safe and confident while getting good mileage. He is a bit afraid to not-even-floor it and hear the engine at full blast accelerating up to freeway speed.

You can "just drive" a Prius V and get very good mileage. Don't baby it.

If you need extra acceleration to keep up with merging highway traffic, go ahead and put your foot down further! And you don't need to worry about going into power mode first - the power is there in "normal mode".

My last car was a 240hp v6 so I know "effortless power". My first car was a 4wd weighing 3500 lbs with 117 hp - less than your v. It had "enough power".

Well your v has more than enough "loud power" - you will get used to it.

Don't worry about the noise - the transmission can handle it and your speed will rise more quickly and you will have enough "oomph" to merge safely. Once you are at the speed you need, things will quiet up nicely.

(Maybe one day you will make catgic's day - and mine - by asking about the inner workings of the hybrid system indicator on the v, but I'm much more concerned that you realize you have a $!@&!@@& great, reliable, versatile car. Have fun!)

 

Actually its about 5K rpm. The hybrid system is programmed to deliver low emissions first, and high MPG second. Lower RPM in a full throttle situation generates a lot more emissions. (and wastes fuel too)

 

You can probably safely assume that the control software Toyota builds into the Prius already incorporates all the best lab data they have on the torque, power, rpm, and efficiency curves of the components they are building in.

Essentially, the hybrid-vehicle ECU decides on a target amount of power in kilowatts that it would like the ICE to be supplying at a given moment. That request is sent to the engine ECU, which aims straight for the rpm and engine conditions that are best for producing that amount of power. The transaxle then delivers that amount of power to the wheels at the appropriate speed ratio.

-Chap

 

You should also a note how this differs from traditional engines & transmissions. In normal cruise mode, the old drivetrains are run at significantly higher RPM than necessary, at a significantly lower level of torque than is most efficient. This is what American drivers are conditioned to expect, allowing some significant torque reserve without gear shifts when road conditions change.

The Prius engine normally cruises at a lower RPM and higher torque. When any more power at all is required, the eCVT ratio must be changed to allow the engine to spin up proportionately much faster than the car is speeding up.

 

When I need it I just floor it to the ground, that gives you less time of high reving sound, because you get up to speed very very quickly

And actually this is not "transmission" fault but low torque of petrol engine. Under low rpm useful (efficient) torque from the engine is only around 100 Nm, that is in the range of small 1.3 NA engine, imagine what would be like to have that small engine with MT in a car that weights as much as Prius. Either you would be getting nowhere or you would be reving that engine to the max to get somewhere.