How the Prius wastes fuel
I often come across eco drivers who do not respect the slower traffic kept right concept, or eco drivers that interrupt the flow of traffic because they are oblivious of anything that is going on around them. There are other vehicles that do this, but the Prius seems to be the main culprit. For years, I have noticed that when I come across an interruption in traffic flow, it is so often a Prius with nobody in front of him that is causing the problem. I respect eco drivers who can do their thing without interrupting the flow of traffic, but have resented the ones who don't for years. Anyway, I started keeping track of what happens when a Prius interrupts the flow of traffic a few months ago, and thought I might share it here.
One of the big things that helps out economy when eco driving, is to not interrupt kinetic energy, kinetic energy being "something in motion tends to stay in motion". A good eco driver knows to not speed up and slow down too much, and to use the friction brakes as little as possible, and this preserves kinetic energy. I have been researching kinetic energy usage for years in the electric vehicles that I build, so I have plenty of instrumentation on board my electric metros for measuring energy usage. I can plot and record graphs of my battery pack, amps, volts, rpm, speed etc, as I drive. When I encounter a Prius that is causing a resistance in traffic flow, I can see that the interruption of my kinetic energy wastes a few watt hours everytime it happens. It is not really all that much of a waste, and I can often make efficient driving choices to minimize the waste, but most cars do not.
Wasting a few watt hours everytime I come across a Prius is pretty trivial if you look at how it effects my fuel economy, especially considering that there are few EVs, if any, as efficient as mine, but if you imagine the number of gasoline cars that waste five times more energy slowing down to navigate past the Prius and the speeding back up after they are past, the fuel waste would be incredible. Wherever the Prius is, there is a resistance in traffic flow that wastes the fuel of all the cars that finally get by.
I see a lot of focus on weight and aerodynamics by those who are interested in fuel efficiency, but not a whole lot on managing kinetic energy. Many knowledgeable eco modders are aware that it is important for eco driving, but I am not sure if many realize just how much kinetic energy we waste while we drive. I have been studying it for years as I build efficient EVs, and I assure all that we waste way more fuel than most realize by not managing the kinetic energy.
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