“Be kind, for everyone you meet is fighting a hard battle” - Often attributed to Plato but likely from Ian McLaren (pseudonym of Reverend John Watson)

Sunday, August 28, 2011


In a previous post I mentioned that I'd purchased (more accurately, my Company purchased) a Lexus CT200h hybrid. I've now run a few tanks full of fuel through the vehicle and, to a certain extent, gotten accommodated to its driving characteristics (not so good) and its technology (adequate but nothing special in 2011). One thing the photo at left doesn't reveal is that this car is SMALL!

The vehicle's propulsion system consists of a small (1798 cc) Atkinson cycle internal combustion engine with a maximum power output of 73 kilowatts (98 horsepower) and two motor generators - one that's engine driven and can charge the battery or provide additional power to the other, a drive motor. It features four "modes": Normal, Eco, Sport (amusingly), and EV. In the EV mode the car can go a bit under two miles at a bit under 30 m.p.h. on battery power alone.

The CT200h incorporates a couple of features that obviate some of the fuel economy measures I employed in the Land Rover LR3 HSE I previously drove. The internal combustion engine shuts off at stops. It also shuts off on downhills, converting gravitational potential energy to charge the battery. It also employs regenerative braking.

With all that, stated candidly, the vehicle is a dog. Why, then, did I select it? It's comfortable, it has a reasonable technology platform, it's quite reasonably priced (by Lexus standards - I got out the door for less than a Chevy Volt would cost before the tax credit), and it's capable of excellent fuel economy. It's EPA rated at 43 m.p.g. city and 40 m.p.g. highway using regular gasoline. In my five tanks full I've averaged about 52 m.p.g though I'd hoped for better. I've not tried the "pulse and glide" method - it's simply more work than I want to devote to fuel economy.

Above is the output of a (trivial) Mathematica program I use to estimate fuel economy. Its prediction in the case of both the LR3 that I used to drive (and my wife now drives) and the CT200h are pretty close to the numbers I actually achieved at the pump. Of course, the calculation is for 55 m.p.h., the fastest I drive.

In the news in the last month, we see that President Obama and "Detroit automakers" reached an agreement to raise the CAFE standards to 54.5 m.p.g. by 2025. Of course, this resulted in an outcry that this is another example of big government interference in the free market and an example of creeping socialism. Maybe it is. But impossible, or even impractical, to achieve, it is not. I'm driving a comfortable vehicle that, while by no means quick or fast, comes close to this without any radical driving techniques (I haven't even tried drafting). As you may have noted, it's currently 2011.

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