Is this normal?

forget your preconceived notions and browse some of the newbe threads to begin to get a real understanding of the car. welcome and all the best!

 

Yes it is normal! The key is to not think so hard about it. The Hybrid Synergy Drive (HSD) is doing more things simultaneously than our minds can comprehend, so following every variable and arrow is bound to be confusing and make little sense. But trust the HSD!

If you're getting over 50 mpg just be happy! Congrats on the new car!

 

Yes all normal. Think of the HV battery as a Electric spring, the engine keeps it compressed about 80%, so that if it need more power it can release the spring, but not all the way compressed in case you hit the brakes hard and it need to absorb that. The yellow arrows are 'topping up' the battery just in case you need it.

Now Toyota can size the engine to be efficient and not worry that it only has 76 HP. If you need more HP, the spring uncompresses to give it to you. If you never need more than 76 HP, it stays compressed. (Apparently ACME went out of business, and no one sells really big springs anymore)

If Toyota let it get down to nothing, you would REALLY only have 76 HP and your car will be a turtle. Gen II does a good job of not being a turtle.

If you run out of gas, and then drive a mile to the station on battery, once you add gas, it will be the slowest car you ever drove. Don't ask how I know this. (Never run out of gas)

Now the paradox, the battery allows Toyota to sell a 76 HP midsized car knowing it will be fast enough for sane customers because of the battery power. But if you the customer want maximum MPG, you will minimize use of the battery and let the engine be efficient.

Never hitting the brakes is more economical than regeneration.

Never using the battery HP is more economical that converting gas to electricity to chemical reactions, then back to electricity and then rotation.

But you will hit the brakes someday, and regen captures far more of that than disc brakes. You will need more power someday and about 35 more HP is waiting for that day in the battery. And on that day your MPG goes down a little. no Biggie, you needed the power.

 

You don't want to use the battery. The more you use the battery, the worse your mileage. Why? Think about it: all of the energy in the battery came from the gas engine, only you wasted some of it by converting it to electricity, changing it to chemicals in the battery, changing it back to electricity, and finally turning it back into mechanical energy with the electric motor. It's much more efficient to directly use the mechanical energy from the gas engine than to go through all of those conversions.

The battery helps by allowing the Prius to work with a small and efficient gas engine, plus it stores some energy from regenerative braking, but it general you should be happy when the battery stays out of the equation.

Tom

 

Hi FirstFlight. It uses the battery more at low speed. Try to use the battery to keep the engine off when you're traveling at low speed and when the grade is slightly downhill. However try not to let the battery deplete too much before the engine cuts back in, otherwise it uses too much gas trying to recharge the battery all the time.

BTW. I've also got a secondhand 2005 model and I get almost exactly the same mileage as yourself. Typically 54 to 57 MPG.

 

This is very informative thread and timely for me since I am probably going to get a 2005 Prius soon too.

I never conceptually viewed the battery as spring until now, but the analogy helps. Plus, until now I thought of the battery/ice as equals, but now I am beginning to see it as an assistive energy source to a very efficient engine.

I still have a lot to learn.