What eats away at brake pads more?

[Vyse]

Motorway traveling with stopping from much higher speeds but less frequently or stop start traffic were you aren't going as fast but are using the brakes more?

[A900ss]

Per mile it will be the urban environment rather than the motorway by a fair whack.

Town taxis use a lot more brake pads than distance couriers.

[otolith]

I tend to consider having to use my brakes at all on the motorway as indicating that I have made a driving error.

[Raman Kandola]

otolith said:

I tend to consider having to use my brakes at all on the motorway as indicating that I have made a driving error.

Yeah i think the same way, You should always be able to control your speed just with the accelerator unless your brekaing due to another drivers error e.g. they slammed on their breaks or if the traffic did come to a sudden standstill for whatever reason

[mrmr96]

Raman Kandola said:

otolith said:

I tend to consider having to use my brakes at all on the motorway as indicating that I have made a driving error.

Yeah i think the same way, You should always be able to control your speed just with the accelerator unless your brekaing due to another drivers error e.g. they slammed on their breaks or if the traffic did come to a sudden standstill for whatever reason

Or they pull out on you whilst you're overtaking.

Quite often I'll be in lane 3 passing cars in lane two, and one will decide he wants to pull from lane two to lane 3 in front of me, whilst doing 10-15mph less than me. I think it happens to me because, unlike most motorway drivers, I leave a safe gap to the car in front of me (rather than driving nose to tail as most seem to).

[otolith]

Can't say that happens often enough to cause significant brake wear, but yes, someone else making an unanticipated driving error can do it too.

[Vyse]

In regard to the motorway breaking, I was referring to when you exit the motorway at a junction.

[Drumroll]

Again leaving/joining a motorway is planned move so generally don't really have to apply the brakes hard.

[Agrispeed]

IRRC hard stops are better than lots of gentle stops for wear.

also, wtf is wrong with people answering questions!

[blank]

It's mostly to do with energy.

So one from say 70 to 30 is a lot more wear than one from 30 to 0.

[Don]

Spelling Police Announcement

Break - smash something to bits
Brake - slow something down

Breaking - the act of smashing something to bits
Braking - the act of slowing something down

Breaks - little rests during work time
Brakes - equipment for slowing something down

Break Pads - stylish holiday homes
Brake Pads - sacrificial element of the braking system

etc

[mybrainhurts]

Breaks...tut

Brakes...deep joy

[mrmr96]

Vyse said:

Motorway traveling with stopping from much higher speeds but less frequently or stop start traffic were you aren't going as fast but are using the brakes more?

Your question is too general to provide an accurate answer for.

As another poster has explained, the wear rate will be related to (amongst other things) the amount of energy you're trying to shed. Kinetic Energy = 0.5 x Mass x Velocity ^ 2. So dropping 30 mph from 70 to 40 sheds a lot more kinetic energy than dropping 30mph from 40 to 10mph.

The reason your question is too general to give an answer "a or b" is that you've not said what speed and what frequency is to be compared. 1 stop from 70mph to 0 will wear the pads MORE than two stops from 30 to 0. But 1 stop from 70mph to 0 will wear the pads LESS than 100 stops from 30 to 0.

Note also that pad and disc wear is also related to the type of brake pads you're using, and what they were designed for. In simple terms brakes use two types of friction; adhesive and abrasive. Abrasive friction is like sand paper, it works well from cold (but crap when hot) but it will erode the friction material. Adhesive friction is like glue, it works well when hot (but crap when cold) and requires brakes to be properly "bedded" i.e. there's a thin layer of pad material deposited on the disc face, and actually erodes the friction material less. Regular car brakes will use predominantly compounds that make use of abrasive friction, as they need to work from cold. Race car brakes will use a compound mix comprising more adhesive material, as they need to work when hot. (You'll not commentators referring to cold brakes being "wooden" on a race car.) I believe adhesive materials also produce more gas when heated, so vented discs help prevent the pads being pushed off the disc surface by providing an escape path for the gas released at the pad/disc interface.

HTH

[gavsdavs]

otolith said:

I tend to consider having to use my brakes at all on the motorway as indicating that I have made a driving error.

^^This.

Was coming back down the m1 and was watching this happen lots yesterday.
People travelling too close and too brake happy.
You could see the lines of 'not concentrating enough' drivers - holding the outside lane but only observing only the car in front, as soon as they saw brake lights they braked too. No simple 'take your foot of the gas a bit earlier'.

The 'compressions' you get on busy motorways appear to be self inflicted on those being too pushy and not looking a few cars ahead.

On the other hand, if I worked in the motor trade I'd say "Carry on, you're doing just fine. See you in a month, I have your replacement pads on order already".

[CraigyMc]

Raman Kandola said:

otolith said:

I tend to consider having to use my brakes at all on the motorway as indicating that I have made a driving error.

Yeah i think the same way, You should always be able to control your speed just with the accelerator unless your brekaing due to another drivers error e.g. they slammed on their breaks or if the traffic did come to a sudden standstill for whatever reason

I used to think this until I got my BMW 320d ED. It's exceptionally good at rolling along in top gear with no fuel being added to the engine.

Now the point where I would have to lift off is often beyond visual range - it'll roll on a flat section of road for more than half a mile from 70mph to about 50mph.

It will also accelerate down various hills in top gear.
There's one hill on the A34 where if you go across the crest of the hill at 70mph, it'll speed up to about 80mph with no gas pedal involvement whatsoever - with a car like this, never using the brakes on a Motorway isn't as easy as you might imagine. I still do it most of the time though.

[Garett]

I would imagine town driving wears quicker. I've had the same pads in the front of my daily for 70k miles, mostly motorway driving, no idea what the life expectancy of a set of front pads is though.

A more pertinent question for brake wear is, what wears pads faster, braking from 70-0 gradually over 0.5 miles or sharply over 300 yards?

[Agrispeed]

Garett said:

I would imagine town driving wears quicker. I've had the same pads in the front of my daily for 70k miles, mostly motorway driving, no idea what the life expectancy of a set of front pads is though.

A more pertinent question for brake wear is, what wears pads faster, braking from 70-0 gradually over 0.5 miles or sharply over 300 yards?

I believe the hard stop is supposed to be better, although I'm not sure why, perhaps something to do with heat building up.

[james_gt3rs]

Agrispeed said:

Garett said:

I would imagine town driving wears quicker. I've had the same pads in the front of my daily for 70k miles, mostly motorway driving, no idea what the life expectancy of a set of front pads is though.

A more pertinent question for brake wear is, what wears pads faster, braking from 70-0 gradually over 0.5 miles or sharply over 300 yards?

I believe the hard stop is supposed to be better, although I'm not sure why, perhaps something to do with heat building up.

They are shedding the same kinetic energy so the wear is the same. A hard stop means you have more time off the brakes, so they can cool more. So on a track day, brake as hard as you can, and if you want to save your brakes then coast a bit before braking, then you have less speed to shed.

[Ren Esis]

Town driving by a considerable margin. I commute to Shrewsbury from Birmingham. The M54 never has traffic on it and once I leave the M6 to join it, I can drive all the way to the end of the Mway without braking (about 40 miles?).

Compare this to town driving where you have to slow down at least once on every street.

EDIT: In distance terms that is.

Edited by Ren Esis on Monday 16th June 15:47

[mrmr96]

james_gt3rs said:

They are shedding the same kinetic energy so the wear is the same.

That's an oversimplication I'm afraid.