Lexus RX 450h ليكزس آر اكس 2009-2010
**********************************[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]By most standards, Lexus’s luxury SUV hybrid, the , has been a smash success since its introduction in 2005. A significant number of Lexus SUV buyers have opted for the “hybrid upgrade,” making the Lexus RX 400h almost as popular as the and the —despite similar fuel economy and a steeper price tag of $42,000. Now, the RX gets an update—and the name will change to RX 450h.
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, while keeping the gas consumption at or below the level of the conventional version.
With this larger powerplant, output will be 295 horsepower—27 horses more than the current RX 400h. Official fuel economy numbers aren't yet available, but the bump up in power will mean minimal (if any) fuel economy improvements over its predecessor. (The RX 400h is rated at 27 in the city and 24 on the highway.) We're not sure why Toyota, the maker of the Lexus brand, is pushing forward with bigger engines when consumers—even luxury buyers—have elevated the importance of fuel efficiency. Wouldn't Lexus buyers gladly trade the extra 27 horsepower for one or two more mpg?
The new 450h is based on a completely redesigned RX line, which boasts sharper styling and a reconfiguration of interior space. The RX 450h hybrid has a few unique styling features, including a stylized grille and front bumper, hybrid badging with blue-trimmed Lexus logos, a 19-inch optional wheel design, and blue-tinted headlamps and tail lamps.
*********************************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.
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.
Aside from these hybrid system advancements, the RX 450h will share most of the technological and luxury enhancements of the new non-hybrid RX 350. The Lexus RX 450h
موضوع: السيارات الهايبرد 
الإثنين يونيو 14, 2010 2:58 pm
Engine
Throttle System
