Although the retail launch of the Toyota Prius Plug-in Hybrid (PHV) isn’t scheduled until 2012, Toyota had a handful of 2010 Toyota Prius PHVs available for test drives during this week’s Mobility Seminar in La Jolla, Calif. The vehicles are part of a pilot program that features 600 Toyota PHVs, 150 of which are located here in the United States.

After a quick tour of the changes that Toyota has made to the PHV version of the Prius, I hopped behind the wheel for a 10-mile trip that combined city driving with a quick jaunt up I-5. My ride-along partner, Wayne from, wanted to stop quickly to take a few photos of the breathtaking ocean views, but I still managed to achieve a 63 to 37 percent EV to HV ratio.

What that means is that 63 percent of the time I was driving, the Prius PHV was in electric-only mode. The other 37 percent of the time the vehicle switched over to hybrid mode. In its current iteration, the Toyota Prius Plug-in Hybrid has an all-electric range (AER) of about 13 miles with a top speed of 62 mph. Once the vehicle crosses that 62 mph mark, the hybrid engine kicks in. Since I drove a few miles on I-5, I did go over that 62 mph threshold.

The EV driving mode in the Prius PHV is a bit different than the non-plug-in version. Most notable is the elimination of the EV Mode button. In the Toyota Prius, drivers can force the vehicle into EV mode by pushing the button. However, this is not possible with the plug-in version. The engine uses EV mode when it can and switches to hybrid mode when it can’t.

Although there is no EV mode button in the pilot vehicles, Toyota has not confirmed that this change will remain once a retail version of the vehicle is available in a couple of years. The removal of the button was actually a point of conversation among seminar attendees with many feeling that it would be beneficial to include the ability for the driver to either force the vehicle into EV mode or to alternately force it into HV mode.

In addition to the removal of the EV mode button, there are some other differences between the 2010 Toyota Prius and the 2010 Toyota Prius PHV. Naturally the most significant change is the charging capability. The driver’s side of the vehicle features a charging door complete with custom Prius PHV badging. The vehicle can be fully charged in three hours using a standard 120-volt outlet. The system is capable of recharging at 220-volt outlet but there is no charging mechanism available during this test phase.

Some other external changes to the Prius PHV include a custom color, silver accents on the mirrors and the hatch, and the flashy Plug-in Hybrid graphics on both sides of the vehicle.

Although the exterior changes let everyone know that you’re driving a Prius, the big change is on the inside. Instead of a single Ni-MH battery pack, the Prius PHV has three lithium-ion batteries. With more batteries comes the need for a more comprehensive cooling system. In addition to the side cooling vents found in the backseat of a standard Prius, the plug-in version includes additional cooling vents under the rear seats. This ensures that the batteries stay well ventilated.

While the 150 plug-ins are being tested here in the United States, Toyota is capturing data about the vehicle’s performance as well as driver feedback. Each vehicle is equipped with a remote data collection device that allows Toyota to gather the following information:

Trip info:

  • Length
  • Percent highway and city
  • EV-mode and HV-mode miles
  • Fuel efficiency in HV- and EV-mode
  • Time of day
  • Length of charging event
  • Battery SOC at beginning and end of charge
  • Energy usage
In addition to the vehicle stats, Toyota is conducting driver surveys before the vehicle is driven, partway through the demo process, and after the demo process is completed. All of these statistics will be available on Toyota’s new Environmental Safety Quality (ESQ) Communications website.

Travel and lodging for this media event was provided by the manufacturer.

Driving the Toyota Prius Plug-in Hybrid
Attendees of Toyota's Sustainable Mobility Seminar in La Jolla, California were able to test drive the Toyota Prius Plug-in Hybrid.