The medium sized Highlander Hybrid was first introduced in 2006, when the Ford Escape Hybrid was already on sale in the U.S. Broadly based on the Gen 1 Prius, adapted for the SUV’s larger V6 engine, battery pack issues were common service issues. As with the earliest Gen 1 Prius, the scan tool was changed for the SUV in 2008, from the former Vetronics Mastertech (which was acquired by Bosch) to the Toyota Techstream (developed in conjunction with Denso, one of Toyota’s key partners). The SUV has a 3.3L V6 power plant. It was not an Atkinson cycle engine, but it did deliver 265-hp total system horsepower. Coupled with an electronically controlled continuously variable transmission, it also provided part-time all-wheel drive. The transmission also presents service challenges. In addition, the Highlander Hybrid fuel economy was rated at 23 mpg combined, lower than all other hybrid SUVs, and well below the 30 mpg rating of the more popular Ford Escape. One to stay away from.