Behaviour modification?

Yes, I put my comments in my "Prime Driving Habits" post!
I have recently started doing what you're describing, driving shorter surface street routes to favor my electric mode!

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I did... back in 2000 with my first Prius... long before Google Maps.

Watching the screen, it became obvious certain routes for more efficient than others.

In those days, there was much less EV available and it was all derived from gas. So, you really watched what bumped the MPG overall.

 

If a car can change our driving habits there may be hope for mankind yet.

 

YES! I've been thinking about this lately. If I take surface streets I can get two round trips (commute) into one charge instead of one and a half. It adds 5 min each way. I found myself getting annoyed at plugging it in everyday at work (wait for an open spigot, move car, plug in, walk to office, wait 2 hours, walk to car, unplug, move car) and with this route, I only have to do that 3xs/week instead of 5 now.
I realized that my old route on the freeway wasn't that much fun to drive in this car anyway. My previous car was small, over-powered, and had manual transmission. Charging up the hill then accelerating hard to get to highway speed was really fun, not so much with this car - even if I ignored the crazy fuel inefficiency, it handles like a tank (in comparison) and I never feel like I'm driving fast.
That rush helped vent frustration. I wonder if the new car is part of my increasing job dissatisfaction?

 

My commute is half city streets and half on a parkway that follows the Mississippi River. Today I weaved home on city streets on a route that involved more turns but resulted in one less Stop sign. I'm going to try that for a couple of days. I'm getting 2 days of driving on a charge but I'm on the cusp of 3. Trying to eek another mile out of it!

 

A good portion of the EV increase you see is the additional regeneration you get on surface roads. There isn't much opportunity to regen on the freeway. It is the main reason the Prius has better city mileage than highway.

 

Full disclosure, I am retired and have two plug-in hybrids: 2014 BMW i3-REx and 2017 Prius Prime. After leaving the Marines in 1975, I resigned seven times, the last for retirement:

With two exceptions, my resignations were driven by contract or projects ending. The exceptions were one personality conflict and the other case, a change in work rules that increased hours without pay.

How I got to and from work never played a significant part of my resignations. Rather, I've always driven calmly (to my wife's angst) or taken public transportation so I can also plan my work day. So it could be driving 'Prius-like' might have given more time to think strategic.

GOOD LUCK!
Bob Wilson

 

I'm not so sure.

I'm assuming that the regen you are talking about is not because you are going downhill.
If you are in traffic and you speed up, then brake you are wasting energy compared to just driving at a constant speed. Yes, when you are using regen you are wasting less than in a conventional car, but you are still losing some energy.

The reason you get better miles/kwh on side streets compared to constant speed highway driving is because you are driving slower and thus have less wind resistance. The slower you go the better until the car's baseline power usage for just being on has a bigger effect than wind resistance.

Mike

 

I use Evtripplanner for route planning on less-traveled and longer routes. I've had times where I've found a 20% reduction in electricity used versus the "obvious" route.

 

Wind resistance is definitely a factor in mpg, but we are discussing total EV miles, which are increased through regenerating energy into the battery, regardless of the source. In any case, in stop and go traffic you have to, well, stop and go. The regen system allows you to save a bit of the energy that is usually wasted as heat. It costs you nothing since you were going to stop anyway. If you were to stop on purpose just to charge the battery, that would be costing you gas dollars. Regenerated energy from normal surface street driving has little or no cost, with the result that the energy in the battery is almost always the cheapest available. Even when the engine is charging the battery, the Synergy Firmware uses what it determines to be excess energy. While the engine will run just to charge the battery, it only occurs when you are parked and your mileage is zero anyway.

 

In other threads, I've heard of our engineer friends talking about attaining better efficiency by reducing need for breaking (driving at the speed that requires less breaking) because regen does not capture full energy expended. I tried it, and confirmed that it indeed increases my mile/kwh figures. Driving slow, like 60mph on hwy, allows me to complete my commute of 36-37 miles in full EV. I have come to enjoy stop-n-go traffic (slow) because PP exells in such condition.

Posted via the PriusChat mobile app.

 

I agree with @3PriusMike. You're only looking at the regeneration side of the stop and go equation. Watch your power bar when you accelerate. It's way higher than at a steady speed because you're overcoming inertia. And that higher current is generating more heat because of resistance in the wires and windings, which is an energy loss. When you brake, you get some of that back, but not all of it because of those same heat losses. It's far far better than with a gasser because a gasser wastes all the kinetic energy as heat and brake pad dust. But it's still a net loss if you have to stop and re-accellerate. (Unless you can supercool the HV cables, battery, inverter, and motors. )

 

I do not agree. What you are leaving out is that you HAVE to stop. You HAVE to waste kinetic energy as heat. And you HAVE to speed up afterward. Whether the energy it is reclaimed or not makes no difference to your energy COSTS. However, if you are able put a bit back into the battery, you are getting something for nothing, or, at least, very little. I spent many decades designing energy reclaim systems and the only cost associated with the reclaimed energy is the cost of the equipment and materials that go into building the system. Now, if you purposely speed up and hit the brakes JUST to recharge the battery, all bets are off. Stupid is almost always costly.

 

Stop talking past each other. Remember the statement you are both answering.

"If you are in traffic and you speed up, then brake you are wasting energy compared to just driving at a constant speed. Yes, when you are using regen you are wasting less than in a conventional car, but you are still losing some energy."

That statement is correct from start to finish. So is this one, except for the misspelling of "braking":

"I've heard of our engineer friends talking about attaining better efficiency by reducing need for breaking (driving at the speed that requires less breaking) because regen does not capture full energy expended."

So, yes, regen is better than no regen if you have to stop. But driving slower so that you can coast is better than accelerating more just to regen later.

 

Forgive me for misspelling "braking" as English is my second language. I appreciate engineers like you whose use of language is so precise. We can learn so much from you guys if we are open to listening.

Posted via the PriusChat mobile app.

 

Although harder to quantify, our Prius also takes pains to operate the engine at peak efficiency using the traction battery to bank or withdraw the gap between the load and peak efficiency. Over time, the Toyota engineers have tuned their control laws very cleverly. Understand I don't object to burning fossil fuels, just burning them stupidly.

Bob Wilson

 

Exactly. Thanks, Lee.