battery SOC and MPG's

In short, you want to draw as little energy as possible from the battery, especially in highway conditions.

This is unsubstantiated, but I feel that you ARE better off using only battery power (if possible) in stop-and-go traffic. Seems to me like the constant required braking is going to charge up the battery no matter what, so the ICE won't just be turning on simply to charge the battery.

 

You'll use up less gas if you have a "full" battery.

You'll use up more gas if you have an "empty" battery.

The key, however, is deciding using what is most EFFICIENT.

For example, the ICE is more efficient at higher speeds, whereas the electric motor is more efficient at low speeds.

Keep in mind, that the battery is charged with "EXCESS" energy that the ICE produces. There are also conversion losses to and from the battery. It will almost always be best if you use JUST gas whenever possible (with no energy going into or out of the battery) except at very low speeds.

 

Bob, what are your "plastic wrap" hubcaps ?

 

All of the energy comes from gas, so ultimately you want to use electricity as little as possible. Ideally you want to drive down the road at low speed so as to reduce aerodynamic drag with no gears and the engine directly driving the wheels. In the real world this doesn't work, so we need transmissions and things like that. With the Prius, try to avoid using the battery as much as possible. There are a few special cases where battery use is an advantage, such as creeping in traffic, moving a short distance, or running down the battery prior to a long downhill, where you are going to recapture energy from braking. In general, however, for the best mileage you want to minimize battery usage.

Tom

 

In Japan, there are two groups of hypermilers on city driving.
One is they are keeping the SOC at 6 bar level.
The other is driving at 4 bar level of SOC. Yes, their level is low, but their theory is ...
when the battery pack SOC is low, Prius engine work hard, or high loaded, or more efficient, to recover the SOC level a little bit for next coasting.

Ken@Japan

 

You won't get excess SOC from freeway driving, unless the ambient conditions are cold and the Prius needs to run the engine more for heat. SOC will only go high after long downhills or when the engine is called upon to make a lot of heat.

Tom

 

As my Day 1 is approaching (waiting eagerly for Friday to come)

I'm just wondering about the following scenario. I expect this to be quite a same also for other fellow members.

During my commute I will drive first couple of miles quite slowly through suburb to reach highway, then next 10 miles quite fast, something like 65mph. And the rest 2 miles very slowly because of other traffic.

Now, if we put aside the fact that it's quite cold in Finland during this time of the year, is my goal to: use battery as much as possible for first miles before the freeway, try to P&G or drive in a normal way?

 

Your goal should be to drive normally. Using the battery is less efficient than using the engine. If all driving was continuous at one speed, then this would be easy. Real world driving doesn't work like this. Greatly simplified, what you don't want to do is drive excessively on the battery or force the engine to short cycle on and off frequently. In stop and go driving, try to anticipate stops and avoid fast acceleration. This will allow your Prius to drive slowly on electric with the engine starting as needed to charge the battery. For steady driving, let the engine do the work. You really don't need to think about it; the Prius does a good job on its own.

Tom

 

Was too cheap to purchase "racing" aerodynamic hubcaps, so I fashioned some makeshift hubcaps to smooth(i hope) airflow over my wheels.