I've owned my 2008 LS600H for just over two months now. A beautiful ride. Comfort, power, and economy. I've found with the weather warming over the last couple of weeks the economy has improved noticably, even though I've driven it a little harder than before on motorway runs since. I had 35.8mpg on a 165 mile run, and tend to get 24-25 around town (I'm in UK so slight different calcs may apply for the galon measurement). The electric motor works wonders in slow stop-start motorway gridlock. I've also found that using the cruise control with adaptive off helps. The engine doesn't brake wasting energy already used,and the need to accelerate for the traffic conditions can be controlled far better. Cancel the cruise control early when you see the need to slow down ahead, let it coast instead of braking and charge the battery in the process. And accelerate lightly at low speed to ensure it's battery alone powering the car. I find the V8 kicks in with relatively light acceleration.