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post #1 of 5 (permalink) Old 03-19-2017, 06:04 PM Thread Starter
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About those regenerative brakes

My recent 17 XLE hybrid purchase is my first ever hybrid. I think I understand that as you apply pressure to the brakes it uses some type of gearing to slow the car and recapture some of the lost energy before ultimately applying the actual brake pads to the disc to further slow of the car.

In my previous (non hybrid) car I used to engine brake all the time (especially downhill) before ultimately engaging my brakes. My pads lasted forever and there is no harm done to the engine or tranny. I notice now with the Rav that when I "downshift" to simulate engine braking, the EV light goes out on the dash, but if I don't downshift and just brake or merely lift from the gas, the EV light engages and stays on. So what I'm wondering is if I engage the brakes on a downhill (vs downshifting) will I ultimately be wearing down the pads sooner due to the increased pressure needed to slow/stop? But is breaking any "better" for the hybrid system for any special reason than using the downshift to slow the car first?

Thanks for any light you can shed.
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post #2 of 5 (permalink) Old 03-19-2017, 09:07 PM
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All braking is bad for efficiency. Regen braking is less bad. Light regen braking doesn't use the friction brakes at all. You have a large power meter in the left of the dash that provides all the info you need. In the regen braking area of the gauge, there's no friction braking till the needle reaches all the way down, then friction braking is blended in. Under 10mph is mainly friction. This is all covered in the manual.
You need to read up on the Prius hybrid drive system. Regen braking is provided by the electric motors that also drive the car. They are called "motor/generators". The more pressure you put on the pedal the more power is generated, and more drag.

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post #3 of 5 (permalink) Old 03-19-2017, 11:15 PM Thread Starter
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All braking is bad for efficiency. Regen braking is less bad. Light regen braking doesn't use the friction brakes at all. You have a large power meter in the left of the dash that provides all the info you need. In the regen braking area of the gauge, there's no friction braking till the needle reaches all the way down, then friction braking is blended in. Under 10mph is mainly friction. This is all covered in the manual.
You need to read up on the Prius hybrid drive system. Regen braking is provided by the electric motors that also drive the car. They are called "motor/generators". The more pressure you put on the pedal the more power is generated, and more drag.
Thanks. I plan to do some more reading. In short though, is there any benefit with the hybrid, to using the simulated downshift feature in order to slow the car instead of just using the brakes?
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post #4 of 5 (permalink) Old 03-20-2017, 07:38 AM
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Thanks. I plan to do some more reading. In short though, is there any benefit with the hybrid, to using the simulated downshift feature in order to slow the car instead of just using the brakes?
Definitely not. You lose about 60% of the regen braking.

2016 Hybrid Limited with ATP.


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post #5 of 5 (permalink) Old 03-20-2017, 12:18 PM
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About those regenerative brakes

Try to preserve momentum and do not use the brake pedal. It takes abit of practice but it will yield good fuel economy.

Instead of regen try to lift throttle gently to decrease speed if you need to take a roundabout or corner at lower speed ahead.

Try to use race lines (look at apex on wikipedia) when going through roundabouts and while cornering. That way you can maintain a higher speed and preserve momentum.




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