By most standards, Lexus�"s luxury SUV hybrid has been a smash success since its introduction in 2005. A significant number of Lexus SUV buyers opted for the �Shybrid upgrade,⬝ making the Lexus RX 400h, as it was previously known, almost as popular as the Ford Escape Hybrid and the Toyota Highlander Hybrid. Still, reviewers at the time questioned the desirability of a vehicle that costs between $5,000 and $20,000 more than its competition but nets a fuel economy boost of only 5 mpg from its hybrid system.
After leaving the original RX hybrid series dormant in 2009, Toyota came back in the 2010 model year with the 450h, which offers more power and significantly improved fuel economy. In other words, they upped the ante�and it worked. The Lexus RX 450h was the most popular hybrid SUV for most of 2009.
What�"s the significance of the shift in the vehicle�"s name-number from 400h to 450h? In the gas-powered versions, the number is a code for the engine displacement�so the RX 350 means the vehicle carries a 3.5-liter engine. Lexus nudges those numbers up on the hybrids, because RX 450h�"s combination of a 3.5-liter V6 engine and rear-mounted electric motor-generator gives it the performance of a 4.5-liter engine.
The RX450h is available in both two-wheel drive and all-wheel drive versions. Most all-wheel drive vehicles compromise efficiency due to extra weight from mechanical components. Lexus addresses this issue by providing regenerative capabilities to all four wheels. The result is a more efficient process of recapturing energy.
More Power and More MPG
The 2010 RX 450h boasts the latest incarnation of Toyota's Hybrid Synergy Drive, which works in tandem with a new and improved gas engine. Two new fuel-saving strategies have been implemented in the hybrid system. One is an exhaust-heat recovery system that reduces the time it takes for the engine to warm up. This allows the idle-stop feature�which shuts down a hybrid�"s engine and allows the electric motor to take over�to engage more frequently and for longer durations, improving fuel economy and reducing emissions. The other innovation is a cooled exhaust-gas recirculation system. This feature boosts fuel economy by reducing engine pumping losses.
Read More... [Source: HybridCars.com]