Does rear brake wear quicker?

[SparkevBlogspot]

I have about 7200 miles, mostly in D. I was looking at brake rotors, and the front still shows some crosshatch pattern. It looks like it didn't wear at all since last I looked 4000 miles ago. But the rear is smooth. Does the rear brake engage as soon as brake pedal is applied? If so, it would make for more rear wear when driven in D.

It seems there would be no question that L would not engage the rear brake until the brake pedal is applied. If so, this would be an argument for driving in L instead of D as much as possible. Until I know for sure, I'm going to stick with L.

 

[StevesWeb]

I experimented for weeks to determine the impact of driving in L all of the time. It causes increased power consumption overall, reducing efficiency. A better practice seems to be to drive in D normally and "downshift" into L when you anticipate a stop, using the brakes only to achieve a full stop.

Using L to do nearly all of the deceleration will certainly reduce brake wear, but you are making the drive train work harder. You pay your money and then you take your choice.

 

[NORTON]

I thought no friction braking action occurs driving in D until you max out the regen potential.

Testing can prove this:
>Get a cheap IR temp reader. (A finger might work,, but be careful...)
>Do repeated stops at different deceleration rates.
>Immediately jump out and measure the brake disc temps, front and rear.

I'll be doing this testing soon.

I wouldn't be surprised if there is no temp rise for most braking duty. Do you feel that little 'bump' around 2-3 mph? I think that is the friction brakes finally kicking in.
Of course panic stops will make the friction brakes work immediately.
Stopping in Neutral will make the F brakes work immediately. In fact, do the last test in N, just for an old school reference!

It may be you have something sticky going on with your rear calipers. Do you exercise the 'Parking Brake' much? I use it all the time to reduce load on the drive unit parking pawl.

Side story:
I came down Pikes Peak in my Volt with the battery at 1 mile range. I just rode the brake pedal like a dumb tourist. The SUV in front of me was doing the same and stunk to high heaven...
There is a Park Ranger safety stop where they read your front brake temp. I heard the Ranger tell the SUV person to "take it easy, they were near the limit". Does anyone know about using L on mnt descents, anymore?

My temps where 75° front and 105° rear. (I told him I was a nerd and asked if he could please measure the rears too!) It was a 65° day.
I gained 75% charge on the way down. The hardest, fastest charge that battery ever had ! I was concerned at the time....
With the Spark EV I DCFC all the time.

So maybe there is a little rear brake application during regen braking to keep front to rear proportional.
Who knows? But we can find out. Let the testing begin !

I find driving in L demanding. And I propose there is zero benefit to the brakes or overall efficiency. Some EV's don't let you coast. You have to make it coast. But this is all, IMHO...

 

[SparkevBlogspot]

It causes increased power consumption overall, reducing efficiency.

The "problem" with L is that braking is so strong that more current is made. With higher current would be more losses. I tried to experiment long ago to see if equivalent regen would result in similar power, but it's hard to do. Driving in L just makes for different driving habit (regen power) than in D. Since I find D more comfortable, I've been using it. But if it results in more brake wear, L might be better, hence my question.

A better practice seems to be to drive in D normally and "downshift" into L when you anticipate a stop, using the brakes only to achieve a full stop.

Using L to do nearly all of the deceleration will certainly reduce brake wear, but you are making the drive train work harder. You pay your money and then you take your choice.

I'd rather not change to L/D so frequently. Also, the drive train wear would be no different. Because the regen would take place at similar levels in D and L when when brakes are applied, only difference would be how gently one would apply regen in L vs hitting the brakes in D.

Now if you're saying different driving habit that result in stronger regen in L, that's a different story. I'm trying to adapt to L driving, but it's a hassle. Then when I drive gas car, I have to re-adapt.

I thought no friction braking action occurs driving in D until you max out the regen potential.

That's what I thought, too, but I saw the brake cross hatch, so I want to be sure.

One thing that's substantial is the presence of crosshatch pattern on front rotors after over 7000 miles of driving. Just WOW! Not sure if picture will come out so link to blog is below, but this is what I mean.

http://1.bp.blogspot.com/-GdVVHJyH4mM/VWJFEXIKp1I/AAAAAAAAAC4/xUXHNGTlXmI/s1600/brake_rotor_900miles.jpg
http://sparkev.blogspot.com/2015/05/vs-gas-car.html

Testing can prove this:
>Get a cheap IR temp reader.

If rear brake is applied gently from the onset of brake pedal, you may not see much change in temperature. But it would be interesting to see the result.

 

[MrDRMorgan]

I experimented for weeks to determine the impact of driving in L all of the time. It causes increased power consumption overall, reducing efficiency. A better practice seems to be to drive in D normally and "downshift" into L when you anticipate a stop, using the brakes only to achieve a full stop.

Using L to do nearly all of the deceleration will certainly reduce brake wear, but you are making the drive train work harder. You pay your money and then you take your choice.

I have been playing with driving in L too and I can see driving in L could reduce efficiency if the driver is not careful about controlling the rate of deceleration. If you decelerate too quickly and find you need to re-accelerate a bit as opposed to coasting, then I expect you would consume more power than using D and just coasting. It is the need to re-accelerate that consumes extra power. I have found it takes some pedal-control learning to figure out the best way to decelerate in L without having to re-accelerate because you slowed down too quickly.

I have been using L for a few days, including a recent 230 mile round trip, and I noticed better regeneration going down long hills while staying completely off of the brakes. In-town driving efficiency seems better too and I have seen this on both my 2014 and 2015 Spark EVs.

 

[emv]

I only use L going down significant hills, it just makes my driving too herky jerky otherwise. (And I'm a big enough jerk as it is) I also prefer the more positive actuation of the stop light with the brake pedal.

To the matter of friction brake usage. The Spark uses "blended braking". Any time you press the brake pedal more than the slightest amount, it uses some friction brakes. Unless I'm misinterpreting what I see using the Torque Pro app it proves it.

In any case, I don't expect the brake pads to be a frequent service item. Regen braking is Raybestos' biggest enemy, my 200,000 mile Prius is still on it's original pads and it seems to use them much more than the Spark.

 

[MrDRMorgan]

I only use L going down significant hills, it just makes my driving too herky jerky otherwise. (And I'm a big enough jerk as it is) I also prefer the more positive actuation of the stop light with the brake pedal.

To the matter of friction brake usage. The Spark uses "blended braking". Any time you press the brake pedal more than the slightest amount, it uses some friction brakes. Unless I'm misinterpreting what I see using the Torque Pro app it proves it.

In any case, I don't expect the brake pads to be a frequent service item. Regen braking is Raybestos' biggest enemy, my 200,000 mile Prius is still on it's original pads and it seems to use them much more than the Spark.

One question and I have not looked into this - when slowing down using L, at what point, if at all do the rear stop lights go on? Since letting completely off of the accelerator causes the car to slow down quickly, the driver behind may not notice my car is decelerating quickly which, in turn, may cause the driver to have to make a panic stop - he will not be happy! I find I do step on the brake pedal but only just before the car comes to a complete stop or I started deceleration too late to make a one-foot stop.

 

[Jedi2155]

From what I understand, if you leave it on L and let go of the accelerator for 2 seconds or more, the brake lights come on. I've noticed it myself.

 

[MrDRMorgan]

From what I understand, if you leave it on L and let go of the accelerator for 2 seconds or more, the brake lights come on. I've noticed it myself.

Thanks. I will check to see if it works.

 

[Nashco]

Brake light function depends on what software you're running. There's a campaign that updates the brake light software (I got this installed recently) and if you're in L and let off the accelerator pedal, the brake light immediately comes on. The old (2014 MY) software didn't flash the light on so easily.

Bryce

 

[MrDRMorgan]

Brake light function depends on what software you're running. There's a campaign that updates the brake light software (I got this installed recently) and if you're in L and let off the accelerator pedal, the brake light immediately comes on. The old (2014 MY) software didn't flash the light on so easily.

Bryce

Do you have the campaign number? I have both a 2014 and 2015 Spark EV.

 

[Nashco]

I don't have it handy, but the dealer can tell you on the phone in about a minute if you're interested to have your car work this way.

Bryce

 

[MrDRMorgan]

I don't have it handy, but the dealer can tell you on the phone in about a minute if you're interested to have your car work this way.

Bryce

OK. Thanks. I will mention it to them when I take it in for the first service appointment.

9 Feb: I asked my wife to stand on the sidewalk and estimate how long it took from the time I took my foot off of the accelerator until the stop lights lit. I drove by at 25 MPH and took my foot off of the pedal at the same point for each test. She said it was about 1 second for the 2015 Spark EV and 1.5 seconds for the 2014 Spark EV.

 

[nozferatu]

Brake light function depends on what software you're running. There's a campaign that updates the brake light software (I got this installed recently) and if you're in L and let off the accelerator pedal, the brake light immediately comes on. The old (2014 MY) software didn't flash the light on so easily.

Bryce

Yes I've noticed that...I cannot get my brake lights to come on at all during regen braking. I tried and tried and just won't happen.

I've not received any news about a software update either. How could I find out about this?

 

[MrDRMorgan]

Brake light function depends on what software you're running. There's a campaign that updates the brake light software (I got this installed recently) and if you're in L and let off the accelerator pedal, the brake light immediately comes on. The old (2014 MY) software didn't flash the light on so easily.

Bryce

Yes I've noticed that...I cannot get my brake lights to come on at all during regen braking. I tried and tried and just won't happen.

I've not received any news about a software update either. How could I find out about this?

I would like to know too as on Friday I am taking my 2015 Spark EV in for the 7500 miles service and to have the infotainment software updated so the display will quit defaulting to degrees C. I will ask about the brake light software update too.

 

[NORTON]

.... I am taking my 2015 Spark EV in for the 7500 miles service and to have the infotainment software updated so the display will quit defaulting to degrees C. I will ask about the brake light software update too.

Yikes, be careful. This is like a trip to the Vet for your car.

Those guys have screwed up a simple 'tire rotations' on this car. Left to right is all they can do. Some forego that procedure. Some cars with directional tires can't have any tire rotations.
I'd politely remind the service writer to remind the tech about this. Or defer it if your tires are not wearing funny. I have directional tires on mine, so I'm set for the duration!

Of course SW loads have to be done at a dealerships, so you are at their mercy for that.
This makes me want to test my 'auto brake lights' function in L, but I don't use L. I drive normal mode.

I find a dozen or two donuts greases the gears. Quality donuts ! You can be their favorite customer that day !

 

[MrDRMorgan]

.... I am taking my 2015 Spark EV in for the 7500 miles service and to have the infotainment software updated so the display will quit defaulting to degrees C. I will ask about the brake light software update too.

Yikes, be careful. This is like a trip to the Vet for your car.

Those guys have screwed up a simple 'tire rotations' on this car. Left to right is all they can do. Some forego that procedure. Some cars with directional tires can't have any tire rotations.
I'd politely remind the service writer to remind the tech about this. Or defer it if your tires are not wearing funny. I have directional tires on mine, so I'm set for the duration!

Of course SW loads have to be done at a dealerships, so you are at their mercy for that.
This makes me want to test my 'auto brake lights' function in L, but I don't use L. I drive normal mode.

I find a dozen or two donuts greases the gears. Quality donuts ! You can be their favorite customer that day !

When I spoke to the service advisor I made sure he was aware the tire rotation is only left to right. He was aware of that. They also need to recalibrate the TPMS when they rotate the tires. I asked if they had "qualified" technicians who knew how to properly update the vehicle's software. He assured me they did. This Chevy dealer in Modesto has been in business for a long time and I do not anticipate any problems. I would have leased my 2015 Spark EV 2LT from them last year but they didn't have any on their lot so I had to go to a dealer 70 miles away to get the one I wanted.

Whether they get donuts or a bag of coal will depend on the quality of their work. My Spark EV has not had a single problem and I want it to remain that way.

18 Feb 2016 - There is a recall for this brake light problem and both my 2014 Spark EV and 2015 Spark EV are affected. The recall number is 155282.

 

[mczajka]

Some cars with directional tires can't have any tire rotations.

And which are these?

.... I am taking my 2015 Spark EV in for the 7500 miles service and to have the infotainment software updated so the display will quit defaulting to degrees C. I will ask about the brake light software update too.

Yikes, be careful. This is like a trip to the Vet for your car.

Those guys have screwed up a simple 'tire rotations' on this car. Left to right is all they can do. Some forego that procedure. Some cars with directional tires can't have any tire rotations.
I'd politely remind the service writer to remind the tech about this. Or defer it if your tires are not wearing funny. I have directional tires on mine, so I'm set for the duration!

Of course SW loads have to be done at a dealerships, so you are at their mercy for that.
This makes me want to test my 'auto brake lights' function in L, but I don't use L. I drive normal mode.

I find a dozen or two donuts greases the gears. Quality donuts ! You can be their favorite customer that day !

 

[MrDRMorgan]

Some cars with directional tires can't have any tire rotations.

And which are these?

.... I am taking my 2015 Spark EV in for the 7500 miles service and to have the infotainment software updated so the display will quit defaulting to degrees C. I will ask about the brake light software update too.

Yikes, be careful. This is like a trip to the Vet for your car.

Those guys have screwed up a simple 'tire rotations' on this car. Left to right is all they can do. Some forego that procedure. Some cars with directional tires can't have any tire rotations.
I'd politely remind the service writer to remind the tech about this. Or defer it if your tires are not wearing funny. I have directional tires on mine, so I'm set for the duration!

Of course SW loads have to be done at a dealerships, so you are at their mercy for that.
This makes me want to test my 'auto brake lights' function in L, but I don't use L. I drive normal mode.

I find a dozen or two donuts greases the gears. Quality donuts ! You can be their favorite customer that day !

Everything was completed and all concerns were addressed including one I did not know about. They even corrected one on my 2014 Spark EV too. Way to go American Chevrolet in Modesto, CA.

 

[nikwax]

Some cars with directional tires can't have any tire rotations.

And which are these?

Those of us who replaced the OEM tires with directional tires. If all the tires are the same size, the only way to do a tire rotation is to remove the tires from the wheels. If the tire sizes are different front and rear and the tires are directional, then there is no combination of rotation that would work.