Test drove today.. Questions for people who know.

What bothers me about break wear is the car is likely to wear out the brakes long before I do. When using ACC there are many times when the car brakes hard enough that I'm sure it is using the physical brakes. I wish it was smarter and would not be so aggressive in many cases.

 

Agreed its not a sophisticated system at all. I only use it in the lightest of traffic, even then it has issues. Twice so far I've been driving on a completely empty highway, not another car in sight, and the brake warning on the dash flashes, the car brakes for a second, then all goes back to normal. Quite annoying.

 

One less brake job? I don't think using the brake pedal moderately uses any friction brake. If you press the brake pedal to slow the car down the equivalent of using the paddles, there should be no difference. Now, if you are talking about being alert and braking early (whether using paddles or the brake pedal), then I agree, you will probably save yourself a brake job versus speeding along and braking hard enough so the friction brakes get applied. In any case, it sounds like you enjoy using the paddles, so keep on using them!

 

I am not trying to be combative . . . but I just don't understand this feature of the Clarity.

If I want to slow down, I will use the brakes. I am not going to use them enough to invoke friction braking, so the effect on capturing the kinetic energy of the car and stuffing it back into the battery is exactly the same whether I use the paddles or the brake. Maybe there are people who need the paddles to keep them from stomping on the brake and blowing through the regenerative range . . . but this is just not a problem for me. Personally I simply find that light pressure on the brake pedal is more natural and easier than using the paddle.

And if I do need to stomp on the brake there's a reason . . . someone pulled out in front of me, or the light changed just at the wrong time so that I have to stop quickly. The paddles don't help in that scenario.

 

I found the paddles to be useful in reducing driver fatigue on long downgrades. There, I can control the speed with the paddles while everyone else (other than those with stick shifts) are using their brakes. Compared to regular cars, regen braking makes your car safer too. On those long downgrades, your friction brakes remain cool for emergency braking while those around you have diminished braking due to hot brakes, and you get that life saving benefit while converting that energy into more range! Win-win!

 

The problem is nobody knows when the pressure or travel on the brake pedal invokes the physical brakes. I always assume the paddles are designed not to involve the physical brakes. So using the paddles should involve saving brake pads and rotors.

 

Have you tried using ACC going downhill. It uses regen to maintain your set speed for you. No need to use the paddles.

 

But the point is, using the brake pedal to slightly brake won't use the friction brake either. No difference in the temperature of your brakes between this and using the paddles. If you prefer using the paddles for some reason, great, I just don't want people reading this thinking that paddles makes a difference in brake wear or heat.

 

But that's exactly the reason I do use the paddles to reduce wear. I know that you can put light pressure on the brake pedal and get regen but who knows at one point you make the the calipers make contact.

 

Although I don't know for a fact, it makes no sense to engage the friction brakes during braking unless your braking need exceeds the maximum regen. Max regen is at the limit of the charge meter (I see it go to the limit when I brake harder). BTW, 4 chevrons with the paddle is far from max regen. It only provides regen about halfway of the meter limit.

 

How do you know when you've reached max regen and the brakes engage?

 

Nobody knows exactly, but based on all that i have read on numerous different EVs, not just the Clarity, there is no logical reason that friction brakes should be activated by pressing the brake pedal as hard as required to slow the car as much as using the paddles does, even at the highest level of regen. That was the point of me posting. If you find using the paddles convenient, knock yourselves out, but it is NOT saving your brake pads.

 

I don't understand your last sentence "it is NOT saving your brake pads". It seems that is exactly what the paddles do.

 

The learned and gracious @AnthonyW in this post provided access to a Honda Service Express document titled "Electric Servo Brake System Description." In this PDF file, you can see a diagram of the Clarity PHEV's amazingly complex braking mechanism. One of the components is called the "Pedal Feel Simulator." The Clarity's braking system completely controls the feel of the brake pedal--it was designed to make it impossible to feel the transition from regen braking to mechanical braking. No matter how you believe Honda programmed the transition and no matter how other automobile manufacturers have programmed their hybrid braking transitions, there's no way to know when the Clarity's brake pedal activates the calipers. The minus (-) paddle, however, never activates the calipers.

 

Thanks Insightman. This is what I thought. We drove our 2008 Prius 180,000 miles (now pushing 200,000 with my son driving it) on the original brakes. No paddles there of course. I could never feel when the calipers activated but just used a light touch on the brake pedal and slowed to stops. With the Clarity I like the paddles because, as you indicated, it does not involve the calipers. With the brake pedal I may or may not be wearing out the brakes and disks. With the paddles I know I'm not.

Good to have confirmation. Good job Honda.

 

When I click on the link, I see the post with the attachments. When I try to look at the attachments, I get an error that I have to be logged in to do that. I was already logged in, and trying to log in from the error page doesn't help. A personal problem?

 

I had the same issue.

 

I checked and had the same problem--it must be due to a limitation of this forum, so I made the Electric Servo Brake System Description PDF available here.

 

Thank you. That link worked fine.

 

How does the “parking brake” fit in?

With all this electronic complexity, it seems that there should be a foolproof backup plan that’s purely mechanical, as is the case in most other vehicles. Unless Honda showed a level of multiple redundancy that satisfied the Feds.

Someone please help assuage my nervousness in this matter!