The RX 400h also boasts a new generation of vehicle stability systems that are as complex as the gas-electric drivetrain. Vehicle Dynamics Integrated Management, or VDIM, goes well beyond conventional traction and stability controls that simply react to challenging conditions. Instead, VDIM anticipates vehicle instability and makes corrections to stabilize the handling. At the same time, it allows the RX 400h to achieve higher dynamic capabilities.

For the most part the brakes feel normal. That's impressive given that every time you use the brakes they recharge the batteries using a process known as regenerative braking. The brakes on the earliest hybrid cars felt strange. Not so on the RX 400h. The only thing about them we noticed was that it was a little more challenging to modulate the pedal for smooth stops at parking lot speeds.

Summary

The Lexus RX 400h offers more power, more features and better fuel economy than the regular RX 330. That may be enough justification for the $4,000-$5,000 premium over a loaded RX 330. A better justification may be knowing that you are driving one of the most environmentally friendly vehicles on the planet, cleaner than electric cars when the big picture is considered. Another justification is a little less tangible: The RX 400h is a technological marvel and would be an interesting vehicle to own.

New Car Test Drive editor Mitch McCullough filed this report from the Kohala Coast, Hawaii.

Model Line Overview

Model lineup:Lexus RX 400h

Engines:208-hp 3.3-liter dohc 24v V6 w VVT-i, 167-hp motor generator, 68-hp motor generator

Transmissions:automatic electronically controlled continuously variable transmission with planetary gear unit for gear reduction and power splitting, electronic all-wheel drive control system

Safety equipment (standard):dual-stage advanced frontal airbags; side-impact airbags mounted in front seats; front and rear curtain airbags with rollover sensor; driver's knee airbag; force-limiting seatbelt pretensioners for driver and front passenger; three-point belts for three rear passengers; ALR/ELR seatbelt retractors on all outboard seating positions except driver; top tether anchors (3) and ISO-FIX bars in the rear seat; ABS, EBD, Brake Assist, Electronically Controlled Brake system with regenerative control; Vehicle Dynamics Integrated Management system (VDIM); all-wheel drive

Safety equipment (optional):none

Basic warranty:4 years/50,000 miles

Assembled in:N