Closer Look: the Hybrid bucket

Recently, I had a chance to spend a week with the Lexus CT 200h F-Sport in which I got unbelievable fuel mileage (6.4 L/100km over 1,700km). On the surface that figure may not seem like a big deal since the CT 200h is rated at a combined 4.6 L/100km. What makes it extraordinary are a couple of facts: first, I wasn’t driving like I was trying to save fuel (read: heavy right foot); secondly, the weather wasn’t ideal for fuel economy. There were snow covered roads, rain, windy conditions, all of which kill fuel mileage because they add drag, which means it takes more power to push the car along.

So, how did the CT 200h get this fuel mileage with a heavy footed driver like me at the wheel?

Well, to explain it, I’ll use a bucket, in this case a hybrid bucket.

Think of a bucket full of water, this will represent your hybrid battery full of electricity. Now, if you use the water (electricity) the bucket becomes empty fairly quickly as a hybrid car takes a lot of electricity not only to move it, but to power all the other systems when the car is not running on gas.

Sooner, rather than later your bucket is empty.

Lexus CT 200h electric supply

The bucket now has to be refilled, and that is a huge problem when it comes to hybrids. You see, unlike filling a bucket with water from a hose which takes just seconds to do, a hybrid battery will only accept a certain amount of a charge at a time – it’s more like filling a bucket using cup loads of water instead of a hose.

Lexus has one of the most advanced hybrid charging systems that relies on the vehicle taking advantage of every instance possible to add a cup of water back to the bucket, even as you drive. Multiple systems gather up available energy and convert it to electricity and put in back in the battery (bucket). The efficiency of these systems is what makes the difference.

So, in essence, even as you are using water from the bucket, the Lexus is essentially adding cup loads of water back to the bucket as you use it.

What this means to you, the customer/driver is that there is more battery power available more of the time, and that means you are using less fuel no matter how you drive or what the weather is like.

The nirvana for car manufacturers is to be able to charge the battery using energy from the vehicle as fast as the power is required, so no fuel is used, but that is still a distant dream.

Lexus has demonstrated that significant gains can be made in extracting energy from a moving vehicle and that in itself is a huge step forward for all of us.

Tags: closer look, hybrid, Lexus CT 200h F-Sport