Source: 2015 Toyota Corolla S Premium Review The Corolla S’s CVT automatic transmission with Sport Mode and steering wheel paddle shifters is what sets the S apart from the other models. The CVT offers seven ratios, though by definition, a continuously variable transmission contains no gears. Toyota engineers were able to mimic the effects of selecting a lower gear when downshifting manually. So I checked at www.fueleconomy.gov to see what Corollas are doing now: 2003 Prius 2015 Corolla Eco 2015 Corolla metric 1 41 42 38 highway MPG 2 42 30 29 city MPG 3 41 35 32 combined MPG 4 89 98 98 passenger volume ft{3} 5 12 13 13 luggage volume ft{3} 6 $4 000 $19 000 $18 000 current price (*) * - sorry, just love the inverted hybrid premium irony! What stirred my interest was the paper "Development of New Continuously Variable Transmission for 2.0-Liter Class Vehicles", Jun Hakamagi, Tetsuya Komo, Ryoji Habuchi, Naoki Nishimura, Masahiro Tawara, and Naoki Tamura (SAE 2015-01-1101). I wasn't aware that Toyota had been pursuing belt-CVTs but Wiki soon identified they are most often found in non-USA vehicles except for the Corolla. So I took a second look. Now if a dense, electric motor system could replace the torque converter, a very interesting, hybrid-lite might emerge. Bob Wilson
The IMA could not disconnect from the engine. Also, the poor control-laws for North America was the Honda problem. A single motor of modest power is all it takes provided it can disconnect from the ICE. Bob Wilson
That is how the Hyundai Sonata / Jia Optima hybrids work ( an electric motor substituting for the torque converter in their otherwise conventional six speed automatic), so it wouldn't surprise me if Toyota is prevented from doing so if Hyundai has patent protection over their method.
At 36/40 mpg city/highway, the Optima Hybrid’s fuel economy is low compared to what its midsize hybrid rivals get. Many test drivers are disappointed with the Kia Optima Hybrid’s powertrain, saying it lacks power, has jarring transitions between power sources at times and delivers a noticeable delay of power from a stop. On the other hand, some critics think the transition between gas and electric power is smooth and they think the Optima Hybrid has plenty of power. 2015 Kia Optima Hybrid Reviews, Pictures and Prices | U.S. News Best Cars Seems not only patent is holding back, performance below expectations is...
And some like the Sonata hybrid. For a first generation hybrid system, it returns fuel efficiency close to a second generation(or is it third) HSD in the Camry. The upcoming second generation may not have a big fuel economy improvement, but it does have a flat trunk floor with full folding rear seats. Nissan is doing what Bob proposes. Front-Wheel Drive Vehicle Hybrid System | NISSAN | TECHNOLOGICAL DEVELOPMENT ACTIVITIES Subaru's system might be the same. The IMA replacement is integrated into a dual clutch transmission; so no torque convertor to start. I'm guessing VW's is like Honda's.
