Impact of KERS on tyre wear

[Dekkerb]

Hi
I saw a post recently that suggested that KERS resulted in the tyres wearing quickly, especially if you use KERS 3. I usually drive Normal and 3 but after seeing that post I've switched to 2. I do a lot of miles 44k since November 21. Have changed fronts once (Falken-good)and rears will need changing soon. Should I stick with 2? Thanks

 

[5teep]

I guess if you use KERS the way it's intended, i.e. level 3 only in town at slow speeds it won't have a noticeable effect on the tyres.
KERS 3 out of town at speed is pointless anyway as it takes more power to get back up to speed than you save. I'm at almost 100k miles driven now and after trying every combination I just leave the settings on default. Rarely I will use level 1 if I'm on a long downhill run so I recharge and don't lose too much speed.

 

[JimD]

KERS is instead of engine or mechanical braking, so there should be no difference.

I believe independent testing has shown that there's no significant difference between EV and ICE when it come to tyre wear - it's mostly down to driving style.

There's a lot of confusion due to the massive amount of lies (sorry, 'disinformation') bandied about in the press and on social media on this subject though.

 

[Dekkerb]

I guess if you use KERS the way it's intended, i.e. level 3 only in town at slow speeds it won't have a noticeable effect on the tyres.
KERS 3 out of town at speed is pointless anyway as it takes more power to get back up to speed than you save. I'm at almost 100k miles driven now and after trying every combination I just leave the settings on default. Rarely I will use level 1 if I'm on a long downhill run so I recharge and don't lose too much speed.

Thanks for the prompt and helpful reply.?

KERS is instead of engine or mechanical braking, so there should be no difference.

I believe independent testing has shown that there's no significant difference between EV and ICE when it come to tyre wear - it's mostly down to driving style.

There's a lot of confusion due to the massive amount of lies (sorry, 'disinformation') bandied about in the press and on social media on this subject though.

Appreciate this useful info, thank you ?

 

[Verdigris]

It makes absolutely no difference to tyre wear whether you convert kinetic energy to heat and dust or into electricity. KERS is much kinder to the environment and your pocket.

Edit: I suppose for a two wheel drive car there may be a bit more wear on the driven axle tyres, with KERS, but there will be a bit less on the other axle, so swings and roundabouts. Driving style makes by far the biggest different. If you drive like a **** you'll wear the rubber out quicker.

 

[Dekkerb]

It makes absolutely no difference to tyre wear whether you convert kinetic energy to heat and dust or into electricity. KERS is much kinder to the environment and your pocket.

Edit: I suppose for a two wheel drive car there may be a bit more wear on the driven axle tyres, with KERS, but there will be a bit less on the other axle, so swings and roundabouts. Driving style makes by far the biggest different. If you drive like a **** you'll wear the rubber out quicker.

Cheers for the update!?

 

[kevin ellard]

Hi
I saw a post recently that suggested that KERS resulted in the tyres wearing quickly, especially if you use KERS 3. I usually drive Normal and 3 but after seeing that post I've switched to 2. I do a lot of miles 44k since November 21. Have changed fronts once (Falken-good)and rears will need changing soon. Should I stick with 2? Thanks

The KERS setting on the car doesn't really change the amount of KERS that the car uses it just changes the way the throttle pedal feels and works.
My guess would be that carefully controlling the speed with KERS set to 3 is easier on the tyres than coasting until the last second and stamping on the brakes.

 

[johnb80]

The KERS setting on the car doesn't really change the amount of KERS that the car uses it just changes the way the throttle pedal feels and works.

Try this, get up to 70 mph with kers 2, take your foot off the accelerator and note the regen figure in the power meter, now switch to kers 3 and see the increase. It changes the maximum amount of regen available.

My guess would be that carefully controlling the speed with KERS set to 3 is easier on the tyres than coasting until the last second and stamping on the brakes.

It should make little (if any) difference to tyre wear, maybe slightly more on the driven axle and slightly less on the other axle.

I guess if you use KERS the way it's intended, i.e. level 3 only in town at slow speeds it won't have a noticeable effect on the tyres.

Where have you dreamt that one up from? KERS 3 should be used all of the time except for icy conditions if the traction /ABS isnt up to the job.

KERS 3 out of town at speed is pointless anyway as it takes more power to get back up to speed than you save.

Nonsense, with KERS3 set you can get anywhere from zero to maximum regen braking simply by changing throttle position. It's never been suggested that you should expect to save the same amount of energy when decelerating that you would need to get back to the same speed later. KERS is only about energy recovery instead of using brakes that wastefully turn it into heat and dust.

I'm at almost 100k miles driven now and after trying every combination I just leave the settings on default.

If that works for you thats great but you are wasting potential energy.

Rarely I will use level 1 if I'm on a long downhill run so I recharge and don't lose too much speed.

Why not leave it in KERS3 and simply set the throttle position for the speed you want, thats all you need to do. When regen braking is in operation, the motor is absorbing energy from the car slowing it down and charging battery. Using KERS1 or 3 wont make a jot of difference if you control the speed by throttle control.

 

[Verdigris]

The KERS setting on the car doesn't really change the amount of KERS that the car uses it just changes the way the throttle pedal feels and works.
My guess would be that carefully controlling the speed with KERS set to 3 is easier on the tyres than coasting until the last second and stamping on the brakes.

The drive mode alters the throttle response, KERS alters the rate at which the motor generates electricity, presumably by altering the current in the stator coils to increase the magnetic field and thus the back-EMF. The faster it generates electricity, the faster kinetic energy is absorbed.

 

[johnb80]

The drive mode alters the throttle response, KERS alters the rate at which the motor generates electricity, presumably by altering the current in the stator coils to increase the magnetic field and thus the back-EMF. The faster it generates electricity, the faster kinetic energy is absorbed.

Right idea, wrong motor type, Permanent Magnet Synchronous Motor is used. The back emf is effectively fed into a switch mode power supply to raise the voltage which in turn if fed into the battery, the more braking we do, the higher voltage and the higher the charge current which loads the motor (generator in this mode) more.

 

[Verdigris]

Oh yes, I'd had forgotten it was a permanent magnet motor.

 

[johnb80]

Oh yes, I'd had forgotten it was a permanent magnet motor.

The right principle though.

 

[kevin ellard]

The drive mode alters the throttle response, KERS alters the rate at which the motor generates electricity, presumably by altering the current in the stator coils to increase the magnetic field and thus the back-EMF. The faster it generates electricity, the faster kinetic energy is absorbed.

Are we sure that the same thing doesn't happen in KERS1 when you press the brake pedal?

 

[Verdigris]

The only thing I use KERS1 for is polishing the brake discs, so I won't fail an MOT in the future.

 

[johnb80]

The only thing I use KERS1 for is polishing the brake discs, so I won't fail an MOT in the future.

There’s no need, pads rest gently on the disk all of the time. My i3 is 7 years old, 97,000 on the clock, I never use the brakes and they’re fine. No use the brakes hard a couple times per week etc, nothing, they’re still fine.

 

[Verdigris]

My car sits for a week or more at a time, in wet West Wales. I've been caught twice for rusty discs with ICE vehicles, in the past, so I'm a bit belt and braces about it. I mostly have no use for KERS1 as I'm over 50 miles from a motorway. It's mostly KERS3 for mountain driving without drama.

 

[johnb80]

My car sits for a week or more at a time, in wet West Wales. I've been caught twice for rusty discs with ICE vehicles, in the past, so I'm a bit belt and braces about it. I mostly have no use for KERS1 as I'm over 50 miles from a motorway. It's mostly KERS3 for mountain driving without drama.

They can get a thin layer of surface rust but thats gone in the first few miles. When I was working offshore my cars would be left on the drive for up to 12 weeks and they usually had rusty disks for the first mile or two, nothing to worry about though.

 

[Verdigris]

I do suspect the garages may have been a bit over-zealous/saw a moneymaking opportunity, so I don't take any chances now.

 

[Gomev]

The KERS setting on the car doesn't really change the amount of KERS that the car uses it just changes the way the throttle pedal feels and works.
My guess would be that carefully controlling the speed with KERS set to 3 is easier on the tyres than coasting until the last second and stamping on the brakes.

I think you are thinking of the driving MODE, not the KERS.

 

[Caramaddy]

An interesting thread. Regarding using KERS 3, brake pad wear will be reduced.

Does anyone have a routine of using the brakes, not necessarily to clean the discs, but to work the slider pins (hope this is the correct term as I am not very mechanical) ?

My previous Lexus hybrid had seized pins due to lack of use from the previous owner. Lubricating the pins was NOT in the service schedule. It was suggested to brake hard at least once a week or put the car into neutral on a downhill slope and brake (not recommended on safety grounds perhaps?)

I would be interested to hear your thoughts on this.

Can the MG be put into neutral safely while coasting?