Battery not fully utilized during uphill climb?

I wonder if that's why the CONST readings for MPG are so off kilter to what people are actually getting ....

 

Thank you thank you THANK YOU !!!!

Just got in from my trip to work this morning. Every other morning with this car, I would:

Accelerate like Grandma
Obsess with the Eco Gauge and try to stay in there
Keep backing off the accelerator and than forcing battery usage
Enjoying my car about as much as trip to the dentist

This morning I just drove it. I:

Accelerated like I had a normal car
I kept the 'Car' display up - the one that says what all the parts are doing at any given time. This forced me out of obsessing where I was in the eco gauge
I backed off the accelerator when I could glide or coast, but I didn't try to force the battery into service on my own
Really enjoyed the drive in today

My CONST reading? 57.8. :rockon: Mind you I started out in my garage (40 degrees) and did a 37 mile drive in 20 degree weather with the heat on at 68 (after it warmed up a bit). No grill blocking, no 42/40 pressure (I'm running at 38/36).

I found a couple of other interesting things as well, which really brought into focus some of the other things you said.

1. The car is more responsive when the battery is full. I suppose that makes sense since I'm not 'paying interest' on the forced battery usage driving pattern from a earlier stretch of road

2. The car is much happier sorting itself out without me trying to outsmart the engineers who designed it. I NEVER saw my INST mileage indicator (that vertical bar next to the speedo) hover in the 50-75 range when driving 55mph. I think the car was too busy paying interest on my battery obsession as noted earlier

3. If you just drive it, the battery works in unison w/ the engine. I suppose that's the whole 'Synergy Drive' concept

Thank you for showing me how to drive my car. I know that sounds silly.

 

Tom, do you have the patent number for it? I would love to read more about it.

 

Exactly. The battery is fairly small in usable energy terms. It is equivalent to only a few tablespoons of gas. And to work properly, the battery needs to provide power when needed, but still have room for regenerative braking. As a consequence, your Prius is always doing a balancing act to keep the battery state of charge (SoC) near the middle. To use our money analogy, it's like having a bank account that only holds $100 - deposit more than that an it gets taken by the bank. The car tries to keep the balance at $60, slightly above the middle, so that you have a little extra money when needed, but still room for a small deposit. When the balance gets near the $100 limit, it starts to spend freely to avoid losing money by going over the limit. When it gets near zero it tightens the belt and puts more into savings.

This is true with several aspects of the Prius. Much of the complaining you read about the Prius comes from people who insist on fighting it. A good example is the climate control system. Initially I played with all of the manual controls, but eventually realized it was better to put it on Auto and adjust the temperature to my liking. It's not perfect, but it's better than fighting.

Exactly. Synergy is the key word. You don't need to be an engineer to make it work. Sometimes it's better to not be an engineer, because we tend to over-think things and try to hard. If you just drive the Prius it does pretty well. Hypermileing is a hobby. If you want to do it, have at it, but it certainly isn't for everyone. Generally it works best to just do the normal good driving things: pay attention to traffic flow, don't accelerate just to stop, try to move at a steady speed, and avoid high speed.

Not silly at all. I'm happy to help.

Tom

 

Is this at highway speed (70 mph) and no more than 6% grade? My Gen II in the Rockies needed some fuel on most downgrades to maintain highway speed, or at best at least no braking. At lower speeds, or steep non-highway roads, regeneration charges the battery very quickly, with or without B mode. It actually charges faster without B mode, since B mode discards power through engine braking.

There is one steep dirt road out at a climbing area that is always very impressive. Driving out, I would drop about 2,000 vertical feet at no more than 15 mph, B mode all the way. The poor little ICE would scream like a jet engine, and the SoC would hit full green bars. You get a nice long EV run at the bottom of that hill.

Tom