TRAVERSE CITY, MI – Toyota Motor Corp. says it will make public results of its tests involving 150 Prius vehicles in the U.S. and 600 worldwide equipped with plug-in hybrid-electric technology.

Justin Ward, advanced powertrain program manager in the fuel-cell and hybrid vehicle group at Toyota Motor Engineering and Mfg. North America Inc., tells attendees of the CAR Management Briefing Seminars it’s too soon to finalize results but that data will be posted on the Internet as it becomes available.

Data collection includes warranty and durability information, Ward says, and also will measure the impact on utilities providing power for recharging.

In the U.S., test cars are running chiefly in metropolitan areas on the East and West coasts.

Ward says Toyota favors what he calls a “blended plug-in approach” using both lithium-ion batteries backed by a small gasoline engine to generate power when needed.

“There’s a significant opportunity to reduce cost in selecting (PHEV) technology,” Ward says, with fuel economy 1.7 times greater than Toyota’s standard Prius hybrid. Toyota’s PHEV could reach the mass market by 2012, he adds.

Introduced 10 years ago, Prius now is in its third generation.

“(The) Prius has matured over time,” Ward explains. “It was not always fun to drive. But now there are no compromises.”

Looking further ahead, Ward says that for short-range driving, battery power alone “makes sense,” with PHEVs for longer-range duty and fuel cells eventually powering heavy-duty vehicles.