Toyota Prius Plug-In Hybrid prototype, tested in November 2010
The 2012 Toyota Prius Plug-In Hybrid isn’t set to go on sale until early next year, but we already know quite a lot about the car.
This is mostly thanks to the fleet of Prius Plug-In Hybrid prototypes running around the country, an early version of which we drove back in 2010. However, some new details of the production car were revealed during a recent press event for the 2012 Toyota Prius V.
After analyzing some of the feedback Toyota received from drivers of Prius Plug-In Hybrid prototypes, the company reportedly decided to make several tweaks to the car before its official launch next year.
Mode selection for drivers
Designed to help overall efficiency, especially on the highway, the changes are said to include the addition of a button that lets drivers choose either an electric-only mode or a more traditional hybrid mode that will blend engine and battery power from the start.
Toyota Prius Plug-InEnlarge Photo
Prototype Prius plug-in hybrids defaulted to electric-only mode whenever drivers started them up, and stayed there as long as there was enough charge to drive the car in electric-only mode.
That meant the battery pack depleted itself during the first 10 to 15 miles of driving, and then the Prius Plug-In reverted to behaving like a regular Prius.
That was fine for around-town driving, where electric-only mode is ideal, but bad for highway driving as the higher speeds quickly sapped the battery.
Now drivers will have the opportunity to select which mode they want, to conserve battery charge for its best use: lower-speed driving around town.
Full pack recharging
Equally important will be the ability to fully recharge the whole battery pack--including for electric-only driving--using the car’s regenerative brakes.
2012 Toyota Prius Plug-In Drive - March 2011Enlarge Photo
Originally, the batteries in the Prius Plug-In Hybrid would deliver 9 to 15 miles of most electric driving before the gas engine kicked in. Once the pack depleted, however, there was no way to recharge the full pack--only the third of the pack that mimicked a regular Prius's pack would recharge.
To charge up the entire battery pack, drivers had to plug the car into a 110-Volt power outlet for 2 or 3 hours.
Now, however, the car’s regenerative mode will reportedly be able to top up the full energy capacity of the pack, greatly extending the electric-only range--a feature the Prius Plug-In Hybrid prototypes don’t have.
Hints of changes a year ago
Toyota technical trainer Dave Lee had hinted more than a year ago that this would be the case, after questions from reporters about this odd omission.
"I would anticipate us making a change," Lee said after media previews of the prototype plug-in Prius fleet . It "would make sense" to use regenerative braking for the complete battery pack, rather than switching on the engine. "What we have in this car," he said in May 2010, "may not be what we offer going forward."
Note that these are just two of a number of tweaks Toyota is planning, though the rest are being kept secret for now.