Luxury brands typically reserve large 12-cylinder motors for their range-topping flagship. BMW has the 760iL and Mercedes-Benz offers it S600, both with twin-turbo 6.0 L V12s. Audi goes the non-traditional route with its 6.3 L motor in a W12 configuration. But Lexus attempts to compete using its Hybrid Drive powertrain (or Hybrid Synergy Drive, if you're referring to Toyota's hybrids).
We first experienced this system in Toyota Camry Hybrid XLE: Technology In a Mid-Size Sedan. However, the LS600h L's approach to fuel efficiency is different. While the Prius and Camry hybrids focus explicitly on economy, this big Lexus tries to give you the smooth power delivery of a V12 with the fuel consumption of a V8.
As a result, we find Toyota's UR-family V8 engine at the LS600h L's heart. This is one of the company's newest engines, with displacements anywhere from 4.6 to 5.7 L. It's the epitome of power and smoothness for Toyota’s mass-produced vehicles. The engine is fully modern, featuring 32 valves, quad camshafts, long-lasting timing chains, and dual variable valve timing technology. The 5.0 L 2UR-FSE serves up 394 hp and 383 lb-ft of torque in the LS600h L. Electric motors boost power output by 75 hp to a combined total of 439 hp.
That means the LS600h L falls short of the 500+ horsepower figures put out by the German competition. Usually, the instant torque from electric motors helps neutralize that difference. But Lexus' LS600h L is by far the slowest flagship sedan. Specifications put the 0-60 MPH performance at 5.5 seconds, which matches some sportier cars. The power really fizzles out up top, though.
As with Toyota's hybrids, the LS600h L employs an electronic continuously variable transmission that utilizes planetary gears to combine the gasoline and electric motors. Since it is an eCVT, the transmission has an infinite number of gear ratios to optimize the powertrain for performance or fuel economy. The eCVT sends power to all four wheels and benefits from a Torsen limited-slip differential. Regenerative braking is enabled through a dedicated drive regeneration motor to harness energy and recharge the 288 V, 6.5 Ah battery pack.
In terms of fuel economy, the LS600h L is rated for 19 MPG in the city, 23 on the highway, and 20 MPG combined. That's not altogether great considering the V8-powered LS460L with AWD is rated for 16, 23, and 18 MPG, respectively. A gain of three miles per gallon in the city hardly seems worth the added complexity of a hybrid system (not to mention the extra weight). The outcome looks even worse when you compare Lexus' economy to Audi's A8L, which is rated for 18, 28, and 21 MPG. You can choose between a supercharged 3.0 L V6 or a twin-turbo 4.0 L V8, with the latter delivering much better performance.
Drive Mode Selection
Lexus provides five different drive modes in its LS600h L: Eco, Comfort, Normal, Sport, and Sport+, theoretically transforming how the vehicle drives. These modes affect steering and throttle response, dampening/stiffness for the air suspension, and power. Regardless of the mode you choose, the ride is always comfortable. Sport and Sport+ feel slightly more responsive, but ultimately you’re still driving a 5470-pound hybrid with an eCVT, which is about as far from sporty as you can get.