ICEs and EVs

[Funkworks]

Should have included the Rimac Nevera in that drag race.

Also the McMurtry Spéirling 1-seater car. Must be hard to get them all at once at the same spot. Not sure howthe Rimac compares to the Sapphire. More crazy hyper EVs are coming. Bugatti, Lamborghini and Ferrari haven't really stepped in the ring yet. If speed and acceleration is still their thing, they have a lot on their plate. And few EVs I know of are known to handle as well as M3's and Porsches apparently do in corners. But I haven't really digged in to find out.

I'll be riding my bike on a block running an old car alternator/generator to charge a 12 volt battery to power a lite bulb on a string and wait in line for Soylent Orange as Green was sold out already

I was enjoying that post until the last part ... ... Just like movie actually



A best-of list in PHEVs:

 

[mach7]

The Chevy Volt does not turn on the brake light when regen braking. Both my Gen1 and Gen2. The Gen2 has a regen paddle behind the steering wheel that is quite effective - I seldom ever touch the brake pedal except for the last 10 feet or so when approaching a stop sign.

As for the brake pedal... My Gen1 didn't have the regen paddle. So I hooked up an OBD reader that could detect at what point the brake pedal travel transitioned from regen to physical brakes. With practice, I could feel it. To save the brake lining, I'd press the pedal just to that limit, unless I needed more retardation. In 70k miles, it never needed new brake lining.

Hans.

Everything posted is correct.

As a long time Gen1 Volt owner I think a little clarification might help.

In Drive (D) if I take my foot off the accelerator the car immediately starts regen braking.
The brake lights will not come on.
If I put the shift lever in Low (L) and take my foot off the accelerator the car immediately starts
heavy regen braking. The brake lights will not come on.
If I press the brake pedal the car immediately starts regen braking and the brake lights come on.
If it is regen or hydraulic, when the brake pedal is pressed the brake lights come on.

I know its a minor point, I just wanted to clarify.

 

[4regt4]

Everything posted is correct.

As a long time Gen1 Volt owner I think a little clarification might help.

In Drive (D) if I take my foot off the accelerator the car immediately starts regen braking.
The brake lights will not come on.
If I put the shift lever in Low (L) and take my foot off the accelerator the car immediately starts
heavy regen braking. The brake lights will not come on.
If I press the brake pedal the car immediately starts regen braking and the brake lights come on.
If it is regen or hydraulic, when the brake pedal is pressed the brake lights come on.

I know its a minor point, I just wanted to clarify.

Actually not quite true....

To check if the brake light comes on, I taped a piece of foil over the center light and had it stick up so I could see it in the mirror.

If you gently press partway on the brake pedal, the light most definitely does not come on. But the OBD tool shows regen.

Had an argument with someone over this, that's why I went to the trouble to do this - so I could show him.

Hans.

 

[CalebJ]

Actually not quite true....

To check if the brake light comes on, I taped a piece of foil over the center light and had it stick up so I could see it in the mirror.

If you gently press partway on the brake pedal, the light most definitely does not come on. But the OBD tool shows regen.

Had an argument with someone over this, that's why I went to the trouble to do this - so I could show him.

Hans.

That sounds more like an oddly adjusted brake light switch than anything else.

 

[jadebox]

I have seen other BMW i3 owners report more than 80K miles on their cars and still no need to replace their brake pads. I may need some brake work done on mine, though, because of rust forming from not using them enough.

 

[Funkworks]

... In Drive (D) if I take my foot off the accelerator the car immediately starts regen braking. ...

I wonder what exactly is a car's deceleration when on neutral (no regen).

With all cars having computers now, manufacturers could make the brake light turn on at any deceleration speed. I do wonder how EV makers decides this. Brake lights could be triggered by a speed trend rather than a pedal switch.

I have seen other BMW i3 owners report more than 80K miles on their cars and still no need to replace their brake pads. I may need some brake work done on mine, though, because of rust forming from not using them enough.

My mechanics have recommended having the brake rotors cleaned. I've had it done, but I do wonder by how much braking distance increases when they're rusted. Some people say they jam the brakes on neutral once in a while to clean them but I don't think this is for everyone. Or safe.

 

[DEmery]

Both of our ICE cars have 85k miles and minimal brake wear. I realize I drive in Montana and can go 50 miles without hitting the brakes, but how are you all driving? Is it stop and go work traffic that does it?

 

[afadeev]

I wonder what exactly is a car's deceleration when on neutral (no regen).

Drive train is disengaged while in neutral, so you will roll as you would in neutral with any other car.
BTDT on i3, and now on Model 3.

With all cars having computers now, manufacturers could make the brake light turn on at any deceleration speed. I do wonder how EV makers decides this. Brake lights could be triggered by a speed trend rather than a pedal switch.

Below is a visual on how BMW did it. Tesla's logic is very similar.
Whenever regen breaking is charging the battery, or brake pedal is displaced, the brake lights are turned ON.

My mechanics have recommended having the brake rotors cleaned. I've had it done, but I do wonder by how much braking distance increases when they're rusted.

The thing about rotor surface rust is that it is a transient phenomenon. Very similar to water on the rotors during a rain storm.
As soon as you press on the brake pedal, the pads start rubbing the rust / water off the rotor's surfaces. Depending on the rust amount, it make take more than a second to get rubbed off, but then you are back to regular braking performance.
Same with driving in a downpour. The first brake application will have pads scrubbing water from the rotor surfaces, and will delay that initial deceleration attempt by about a second.

Rust on the non-contact surface areas of the rotor is immaterial.

Some people say they jam the brakes on neutral once in a while to clean them but I don't think this is for everyone. Or safe.

If you think that braking, including ABS-braking, is not safe, I'm worried for you.
There are FAR too many people driving around who are afraid of using the brakes to their designed potential. The first thing I do when I rent a new car (after adjusting the side mirrors and steering wheel position), is test the brakes as I drive off the rental car lot. Some brake pedals grab early, some late. Some rental sh!t-boxes don't have ABS at all, and I would much rather find out that our early and safely, then when I truly need to rely on the brakes in an emergency.

Long story short - if you see rust on your rotors after a drive, you did not brake enough.

Incidentally, that has NEVER happened on any of my EV cars.
However, it does happen regularly on my ICE car that is parked outside, and is exposed to the elements. A quick drive with healthy brake application cures the problem 100% of the time.

HTH,
a

 

[Art Upton]

I wonder what exactly is a car's deceleration when on neutral (no regen).

With all cars having computers now, manufacturers could make the brake light turn on at any deceleration speed. I do wonder how EV makers decides this. Brake lights could be triggered by a speed trend rather than a pedal switch.


My mechanics have recommended having the brake rotors cleaned. I've had it done, but I do wonder by how much braking distance increases when they're rusted. Some people say they jam the brakes on neutral once in a while to clean them but I don't think this is for everyone. Or safe.

On my non-daily drivers I have and had in the past I had to jam on the brakes to clean the rotors, but there was no need on the ICE for putting it in Neutral

 

[Tyeeking]

Both of our ICE cars have 85k miles and minimal brake wear. I realize I drive in Montana and can go 50 miles without hitting the brakes, but how are you all driving? Is it stop and go work traffic that does it?

To your point, I have a Ford F-250 diesel. Tow a 5,500 pound boat and haul a truck bed camper. A tad over 70,000 miles and I’m sitting at 50% brake wear and original rotors. Mostly highway driving but with a load. So much of brake wear (fuel economy too) is how one drives.

 

[afadeev]

Both of our ICE cars have 85k miles and minimal brake wear. I realize I drive in Montana and can go 50 miles without hitting the brakes, but how are you all driving? Is it stop and go work traffic that does it?

For me, it's track that does it. I get ~2mm of brake pad wear per track day (four 30 minute run sessions). New track pads come with 12-16 mm of pad thickness (varies by model), so that gets me 5-7 track days (I chuck them once they are down to last 2mm, assuming even wear).

With an EV, stop-and-go is mostly a one pedal driving experience that recoups kinetic energy back into battery charge. Near zero brake wear. Gentle rotor scrubbing when brakes are engaged to hold the car in place at a stop light.
It's pretty rare that I have to lean on the brakes during daily drives, unless I'm in a hurry, or during deer mating seasons.

Having said all that, I've just replaced pads and rotors on all four corners of our minivan after 37,500 miles. It's the worst handling and the heaviest vehicle that sits outside, but also had a stupid pedal for emergency brake. I think my wife drove around one too many times with the emergency brake partially engaged. Long story short, right rear pad was worn off to the backing plate.
Model 3 is still on the original pads after 55K miles, and pads are about 1/3 worn.
I check all pads on all cars during the regular every-other-year brake fluid flush routine (every spring on the track car).

HTH,
a

 

[Funkworks]

Both of our ICE cars have 85k miles and minimal brake wear. I realize I drive in Montana and can go 50 miles without hitting the brakes, but how are you all driving? Is it stop and go work traffic that does it?

Stop-and-go for me yes. Aweful lately. But an EV is wonderful in stop-and-go. That's not what causes brake rust though. The fact that touchless electromagnetics brake the wheel instead of brake pads is why rotors rust (and water/O2). Bare metal always "rusts" (oxidizes), but in ICE cars, the pads keep cleaning it off.

Drive train is disengaged while in neutral, so you will roll as you would in neutral with any other car.
BTDT on i3, and now on Model 3.

Yeah I know but it still slows down. EV brake lights could be triggered to turn on at the same rate, which would be a bit sooner than when the pedal is released.

Whenever regen breaking is charging the battery, or brake pedal is displaced, the brake lights are turned ON.

Makes sense. Seems like the simple and obvious thing to do.

... it make take more than a second to get rubbed off, but then you are back to regular braking performance.
Same with driving in a downpour. The first brake application will have pads scrubbing water from the rotor surfaces, and will delay that initial deceleration attempt by about a second.

Sounds ridiculous to have rotors cleaned for $100 when you can do it in a second.

If you think that braking, including ABS-braking, is not safe, I'm worried for you.

Don't be worried for me. I'm thinking if everyone did it, we'd have a lot more rear-enders and whiplashes. Many drivers below 20 and over 70 out there. You just have to find a clear place to do it. I always have lots of cars around me. Braking is one thing. "Jamming" to me is another. But maybe you're saying regular braking is enough to clean rust off the brakes. I was thinking being on the verge of making the tires squeal. Don't really want to see everyone doing that. I know my aunties won't.

Long story short - if you see rust on your rotors after a drive, you did not brake enough.

Having a camera down there would be interesting. I'd like to see myself how long it takes for rotor rust to rub off.

 

[Art Upton]

To your point, I have a Ford F-250 diesel. Tow a 5,500 pound boat and haul a truck bed camper. A tad over 70,000 miles and I’m sitting at 50% brake wear and original rotors. Mostly highway driving but with a load. So much of brake wear (fuel economy too) is how one drives.

Well YEA, that was built to be "Ford Tuff", can't compare to a low cost commuter car. I needed new brakes at about 50K and now need them again at 99.8 K on my commuter

Edit: my Tundra probably won't need new brakes in my life time.

 

[OverTheTop]

But maybe you're saying regular braking is enough to clean rust off the brakes.

Yes.

Your EV should be using the dynamic braking down to a low speed (few mph) and then using mechanical brakes for the final stop. That should be enough to keep the surface rust off the rotors I would think.

 

[Funkworks]

Yes.

Your EV should be using the dynamic braking down to a low speed (few mph) and then using mechanical brakes for the final stop. That should be enough to keep the surface rust off the rotors I would think.

If my mechanics are honest, it's not enough. I'd have to make some kind of visual inspection pre- and post- rust, pre- and post- braking, myself to know for sure.

 

[jderimig]

I changed by Volvo s60 front pads at ~90K when replaced my struts. About 60% worn. Its all how you drive. (and 336mm rotors help too).

EV's still need new struts after a while, its not about the brake pads....

 

[OverTheTop]

If my mechanics are honest, it's not enough. I'd have to make some kind of visual inspection pre- and post- rust, pre- and post- braking, myself to know for sure.

I guess salt on the roads might not help either, if you are in those sort of areas. We don't do that here.

 

[Art Upton]

If my mechanics are honest, it's not enough. I'd have to make some kind of visual inspection pre- and post- rust, pre- and post- braking, myself to know for sure.

I've had Mechs offer to clean my rotors after the winter storage of my 'Stang ; About 5 or so mins of aggressive driving with aggressive braking cleaned them for no fee.

 

[Art Upton]

Also as said above, my commuter when it was very wet out you had to be careful before getting into heavy traffic. Pull out of the drive way, move forward and brake. Move forward and brake, then move up to the intersection of larger traffic.

 

[Funkworks]

EV's still need new struts after a while, its not about the brake pads....

Not sure how this relates to EVs in particular. I had to replace struts on the old V6 Merc.

I've had Mechs offer to clean my rotors after the winter storage of my 'Stang ; About 5 or so mins of aggressive driving with aggressive braking cleaned them for no fee.

Oddly, I don't drive aggressively anymore. I think it has to do with wanting to stretch out my battery life. The longer the battery lives, the cheaper the car is per year. My habits changed, but I'm safer too so I guess that's good. I've had lots of fun with handbrakes in freezing weather with no one around

 

[Art Upton]

Ok, spend $100 instead of a few mins of acceleration and braking in an area that is very low risk.

I see you live in low earth orbit preventing the view of Venus , so there must be a huge amount of places you could do this <JK>

 

[Cape Byron]

In sub-tropical climates you get a small amount of surface rust on your rotors after being parked for a couple of days. Just tap the brakes a couple of times while you're barely moving and they are clean again.

Doesn't matter what kind of vehicle you're driving.

 

[Funkworks]

Ok, spend $100 instead of a few mins of acceleration and braking in an area that is very low risk.

In sub-tropical climates you get a small amount of surface rust on your rotors after being parked for a couple of days. Just tap the brakes a couple of times while you're barely moving and they are clean again.

Next time I bring my car to the garage, I'll make sure to brake on neutral a few times on the way.

If they don't say I have rust, then the 1-2 sec rub really works and the mechanics are honest.
If they say my brakes need cleaning, then either they're lying and/or some internet forum people are with that 1-2 second rub ...

 

[Art Upton]

Are you still paying $100 to clean rotors or just brake to clean them ?

 

[Funkworks]

Are you still paying $100 to clean rotors or just brake to clean them ?

Only had car 2 years, and I think I had it done about 14 months ago. Some other forums say my Hyundai brakes happen to be lower quality and seize more easily than brakes of better cars and so I should have rotors cleaned once a year. They do in fact seize (lightly) once in a while when parked in the rain. As I said, next time I go in for a tire change, I'll brake on neutral on the way to see if the shop says anything about the brakes.

 

[Art Upton]

I have an Elantra GT commuter ; when wet you just brake to clean the water off,

 

[kuririn]

Just to be clear, are the technicians cleaning or machining the rotors?
Cuz rotors can get scored by the pads.
Machining them brings back a smooth surface,

 

[Cape Byron]

I have an Elantra GT commuter ; when wet you just brake to clean the water off,

Warning for those who regularly drive through deeper water...

Be careful of driving through water (over the axle) and then soon after applying the handbrake / auxiliary brake / parking brake and leaving it overnight. The secondary brake caliper pads can be locked in place by surface rust (which is usually of no consequence if the handbrake pads are dry). Leave the car in gear, handbrake off and chock a wheel. In the morning, reapply the handbrake only after a short drive and applying the normal brakes a few times to heat the rotors slightly.

CAUTION: If you do end up with you handbrake locked on - let off the handbrake, give it the berries* in first gear or reverse and drop the clutch. Ignore the noise of the pads breaking through the rust. Or, you can have your car towed and let your mechanic do the same thing when you're not watching. He will charge you $300+ and your towing fee.

As ever: YMMV, don't try this at home, etc, etc, etc.

*3,000-4,000 rpm in the RAV4 sacrificial test vehicle.

 

[Funkworks]

Just to be clear, are the technicians cleaning or machining the rotors?
Cuz rotors can get scored by the pads.
Machining them brings back a smooth surface,

I actually have no idea what tools they use to remove the rust. If it's somekind of spinning bit, I'd call it cleaning if the bristles are plastic and machining if the bristles are metal. This sort of rephrases my question: just how hard is it to remove the rust? Is a 1 second brake pad rub enough? What grit of sandpaper would I need? Does one need power tools?



Until I bother to take 3 minutes and look it up on some youtube video, I'll never really know.

 

[Art Upton]

Warning for those who regularly drive through deeper water...

Be careful of driving through water (over the axle) and then soon after applying the handbrake / auxiliary brake / parking brake and leaving it overnight. The secondary brake caliper pads can be locked in place by surface rust (which is usually of no consequence if the handbrake pads are dry). Leave the car in gear, handbrake off and chock a wheel. In the morning, reapply the handbrake only after a short drive and applying the normal brakes a few times to heat the rotors slightly.

CAUTION: If you do end up with you handbrake locked on - let off the handbrake, give it the berries* in first gear or reverse and drop the clutch. Ignore the noise of the pads breaking through the rust. Or, you can have your car towed and let your mechanic do the same thing when you're not watching. He will charge you $300+ and your towing fee.

As ever: YMMV, don't try this at home, etc, etc, etc.

*3,000-4,000 rpm in the RAV4 sacrificial test vehicle.

We do not get that deep water here, it is just sitting in a driveway during a rain storm... The Hyundai has been the most sensitive car to that brake problem... [and costing the most to fix the brakes at 50k] more so then storing my 'Stang all winter long when I had it before I traded it and the Silverado for the Tundra.

When it blows it's GDI motor that burns too much oil between changes I will replace it with a Toyota