Comment by tonymet | Hacker News Reader

Comment by tonymet | Hacker News Reader

You can get similar results with proper deceleration, engine braking and downshifting. I’ve had brake pads last 110k miles (with room for 20k+ more), even though I lived in moderate hilly area. That’s probably 1/3 the brake dust, and comparable to an EV .

If you are getting lower MPG than the EPA rating, you are also burning up your brakes from heavy deceleration. Improve your MPG to 15% over EPA and your brakes will last a lot longer.

Also their studies were in European markets with tiny EVs and low speeds. Americans are favoring 7k-9k lb EVs (Hummer, Rivian), with massive brake rotors and PADs— at highway speeds 75mph+. A good driver of a 3k lb vehicle will produce less brake dust than a typical driver of a 9k EV.

Studies like this are helpful, but they are not comprehensive. Similar to the marketing that home LEDs would have 10-20 year longevity, yet in practice they burn out after a few years. The full supply and application chain has to align for the ideal results in practice.

But in a manual transmission car, downshifting and engine braking produces clutch dust instead of brake dust (basically the same thing).

In a modern car, or if you adequately rev match, the clutch wear is extremely small. Only if you are aggressively down shifting will that be a problem. It’s also only wear at that point in time, not the entire time through engine braking.

exactly!

Well, that's just not true at all now is it?

Anecdotally, every car I've been in where the driver talks about engine braking is rode hard and put up wet. Humans seem pretty bad at downshifting/engine braking outside of vehicles designed for that purpose like big rigs. Cars have much fewer gears so it's harder to align the downshift.

Of course there's little use in having this conversation since we all think ourselves above average drivers. I've had acquaintances reply "I don't even need a clutch I can shift so smooth!" (Do not attempt.)

automatic transmissions engine brake as well. most drivers don't use it, a shame. I can smell the ozone on long descents. if they downshifted their automatic, hardly any braking would be needed would be needed.

Mine engine brakes, but it's true that it wouldn't be smart enough to engine brake going downhill. This is my first automatic after a couple decades of manual. It would be really nice improvement for automatics.

There are _moments_ where I would like to exercise more control, like the long downhill example or maybe staying in a low gear in bad weather.

But, I'm still unconvinced that engine braking on a manual transmission in a consumer sedan for every stoplight is helpful. Cars weigh a lot, simply let off the gas a few seconds earlier.

yeah i agree stoplight clutch braking is unnecessary wear.

not quite. Think of a 2 mile descent. The clutch is only engaged for a fraction of a second. rest of the 2 miles is engine braking.

When done properly , clutch wear is minimal. My clutch lasted > 150k miles and still going

> If you are getting lower MPG than the EPA rating, you are also burning up your brakes from heavy deceleration. Improve your MPG to 15% over EPA and your brakes will last a lot longer.

100%.

People need to understand that the brake pedal is an evil device that converts your cash into brake dust and heat, so use it as little as possible.

Stop accelerating so much in stop-and-go traffic. Drop the "You have to tailgate or else people get in front of you" nonsense attitude. Release the gas sooner when approaching a red light. And for fuck's sake, stop hitting the brakes when you're only trying to shave off a couple mph, especially when going up hill.

I've gotten better-than-EPA mileage on every car I've owned, and I don't even drive slow. Always at or slightly above the speed limit. Economy is all about speed management, not absolute speed, until you're going 75+ mph.

well said

brake wear is also an indicator of overall abuse on the vehicle. If you drive chill, your car will last longer.

I broke an engine mount from heavy acceleration (and hitting a huge pothole) . A lot of strain is put on the chassis from gassing and braking.

Upvoted for making sense of basic physics.

Another factor is speed.

tried to capture that via EPA MPG ratings. if people reduce acceleration & top speed they can save a lot of brake wear

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