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Does regenerative breaking help to SAVE break pads??

I've seen recent posts to suggest this. I was under the impression that while regen breaking was very good for increaseing range, it actually "wore" the pads more since the MS ends up breaking more than an ICE car...just by lifting off the accelerator. (I thought my DS had told me this.) The posts I've read suggest that I was mistaken?? If so, fantastic. Can someone please confirm?

Btw, does TM suggest how often (# miles) the breakpads would be expeced to last under "normal use"? Thanks for your help!

Regen slows the car through the motor, it does not use the brake pads at all. Brake pads are only used when the brake is applied, which is separate from regen. My Prius was on its original brake pads at 123,000 miles with usable life left. I offer that information because the Prius also uses regen.

Thx AmpedRealtor! Appreciate it.

Even though its a sport car, your pads will last you a very very long time. An electric motor also acts as a generator when it is used for slowing the car down, storing the energy in batteries rather than losing it as heat through friction between brake discs and brake pads. Much more efficient and saves your pads.

BEST OF ALL: NO MORE BREAK DUST !! YIPPEE

201w77:
Just make sure to set regen to "Normal".
With regen set to "Low" you may wear out your brake pads faster than a bunch of forum posters learning how to spell brake.

Especially try to avoid break dust. Brake dust is messy, but ...

We have an '08 Roadster with over 60K miles on it and less than 20% brake wear. I think that should be good enough evidence to confirm.

As a car guy who loves mechanical devices it is heaven to slow down electromechanically.

I no longer feel the agony of riding when my wife drives and the pain every time she accelerates just to hammer the brakes. I can feel the calipers closing the poor helpless pads onto the rotors and the extreme heat and dust being produced as all the mechanical parts undergo the stress of wasting all that kinetic energy and converting it to heat.

It is a pure zen like experience to feel the gentle and pure application of magnetic fields pushing gently against each other in total harmony as they gather up that kinetic energy and place it gently back into the batteries.

Regen braking is a holistic experience for those of us that visualize every mechanical component as it is operating.

The only time I use the brakes on the Tesla is the last 5 MPH to come to a complete stop. Better than.......well not quite.

@Roamer

How poetically said - and how true. Bravo!

Robert

Regen breaking drastically reduces wear on the brakes (as stated above), but I suspect the rear tires may experience more wear from being torqued by the slowing motor... I don't have evidence to back that up, it's just my speculation.

If you ever drove a manual transmission ICE vehicle and always down-shifted to help slow down (rather than just breaking in gear), you likely noticed that your break-pads lasted much longer.

In the MS, it very similar, except it's automatic, and completely smooth.

@Tiki

Did you ever notice increased wear on rear tires from downshifting? I'm guessing not, but maybe I'm wrong.

Garth - I've heard a Toyota engineer talk about that, he confirmed that it would probably increase wear over time.. That's one reason I was interested in the AWD - if regen was applied to both the front and rear, it might even out the wear.

Chrisdl - "Brake yourself before you break yourself", is what my driving instructor told me. Also sounds vaguely similar to some old rap lyrics.

That's why the signs tell truckers to use their gears and not their brakes to slow on steep grades. The ones that don't end up on the runaway ramp.

Garth:
Slowing down by turning kinetic energy into heat to reduce a wheel's rotational speed or doing the same by turning it in electricity does not make a difference on the tires wearing out. In fact, with normal brakes you're more prone to block a wheel or activate ABS which will wear out your tires faster than the smooth regen braking.

Sort of a related data point---I sold my 2009 Lexus GS450h when I got my S. I drove it 4.5 years and it had about 80k miles. High performance (0-60 in 5.8) and I drove it hard. With the Toyota/Lexus hybrid system and the regen braking as implemented, I had only 20% front brake pad wear (and nil rear brake wear). I would expect that the Brembo pads on the S will last a long, long time if you use Standard regen. YMMV.

Tire wear may actually be improved. Hard braking puts more load on the front wheels than rear as the vehicle weight distribution shifts forward.

Regen slowing would obviously put a little more wear on the back.

Regen could provide balance.

Garth - sorry, I wasn't clear. Regen would increase rear wear RELATIVE to the front (with regen on the back), but it would be less than brakes would cause.

Need more coffee.

@garth is correct, TM says the rear tires wear faster- both due to regen (when brakes are used, all four tires slow the car, but in regen only the rear tires are involved) and because the car is rear wheel drive.

That's why tire rotation is recommended at 6000 mile intervals, which is quite frequent.

Two different duscussions are mixing up in this thread:

1) rears wear our faster than fronts, due to acceleration and, to a lesser amount, regen

2) rears wear out less from regen than from regular brakes

If you drive too carefully, you might have to change the brakes beacause of rust not the wear.

The regen's impact on wear is minute in itself. It can only enhance and already existing misalignment issue in the rear, if anything. But the
appropriate response is to fix that issue, not use less regen. Regen
is way too mild to wear the tires. Acceleration is what causes 90% of
it in normal circumstances and probably about 30% if you have alignment
issues. Those are what pulverizes tires. They need to make a more systemic
and permanent solution for that.

I drive a manual 928 and use the gears to slow the car most of the time - I do not drive slowly, but don't ride the brakes. The last set of pads lasted 230,000km. I'd expect regen would have a similar, perhaps better result.

@Mark

using engine braking is the proper braking procedure (even taught in driving schools) for manual gearboxes. It does increase brake pad life substantially but it does increase clutch wear somewhat also. A bit of a tradeoff..

Even when I drive an automatic, I often drive them in manual mode and use
engine braking (if the car has this poorly set up) and hypermile :)

I even did it in an Aston martin and saved some 5l/100km in city driving but
would advise against it because they aren't very durable and the gearbox
costs a fortune.. So depends on the car. Porsches are much more durable,
so it shouldn't be a problem. Just can't remember if the 928 is the one
standing out for above or below average Porsche durability?

I am always amazed that people who are educated enough to afford a Model S yet don't know the difference between breaks and brakes, breaking and braking, etc.

To the OP - you can edit the title on original posts by hitting the top left of the post, where an edit handle will pop up.

PD...give me a brake!

Hoo seys u hav too b edumcated 2 bye a modil S?

Often times it is the auto correct which screws people's posts. Depending on device used, mine screws up everything me continuously..
One more reason for the need to have an edit function..

Yeah, and some want autocorrected autos? Bad idea.

Car t Man:

I've never been worried about the way that I drive being bad for the car - I drive fast but smoothly and can and do heel/toe minimising shock on the transmission and clutch, and minimising brake wear.

My Gt_Four (All-Track in the US) Celica's clutch needed replacement after 200,000km of primarily city driving, using engine braking constantly. My 928 now has 407,000km on it and is a '90 GT that I've owned for 13+ years as my daily driver here in Sydney NSW. I have put 2 clutches in it during that time - pretty good in city traffic. At 343,000km my mechanic removed and rebuilt the engine pre-emptively. There was no appreciable wear anywhere in the engine. The heads were sent to be reconditioned but were returned after simply being cleaned as even the valve guides showed no wear. The bores and pistons, were perfect, and all that was done was new rings, bearings, various bolts and gaskets were fitted.

There are lots of people with 'helpful' information about 928s, 944s and 924s. Most are completely wrong, including people telling me my car was a flat 6, that the engine was from an Audi, that they were terribly unreliable etc etc. Here in Australia the 928GT was $AU236k (in those days $US180k) plus on road costs in 1990. Unfortunately many current owners cannot maintain them adequately or use the wrong oils in them killing them.

Its a bit like a Tesla, I have also heard lots of wrong information from 'experts' when they hear that I am a reservation holder, like the 928 'experts' most of the information is wrong.

The model S will be my new daily driver and my biggest worry is that I will be unhappy with the handling and seating support. My 928 is the most impressive car that I've driven other than the roadster, which I considered. The roadster is just too impractical to have as my primary car as my wife's car is a BMW Roadster. It will be hard to give up the 928, I still love it and have not found another vehicle to replace it apart from a V8 Vantage. Since I'd rather buy another investment property than an $AU220k Aston I've kept the 928 for a very long time. I've been waiting for my Tesla as a reservation holder for nearly 2 years now! The price rises combined with the currency fluctuations have increased the price of the car by 20% (ouch).

Back on topic... drive sensibly and use engine braking and your brakes will last a long time. :)


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