101–110 of 115 posts
Earlier quoted context omitted.
Is this (jake brake) what the parent comment was referring to that newer automatics finally do?
Nope. That was reference to automatic transmissions not up shifting immediately every time you decrease throttle.
Earlier quoted context omitted.
It really depends on your building too. I live near a highway and getting around by car is really convenient as a result. Highway noise is not very audible due to the construction of the windows and the walls. My air quality meter says the PM1.0, PM2.5 & PM10 counts are 3-1 ug/m^3 inside and I don't have air filters on.
I live next to a highway and am concerned about air quality too, what meter do you use?
Earlier quoted context omitted.
Whatever the effect, it's at least getting better. As someone who rides a bike to work every day on urban roads that are usually congested, the recent rise of hybrids, and even just cars with auto start-stop systems, has been a blessing. It used to be that driving next to a line of stopped cars was a nightmare, but now at least half of them have their engines off, if they have an engine at all. Moving an automobile a…
> Moving an automobile a couple miles in a dense urban environment at very slow speeds shouldn't require much energy, at least from a pure physics standpoint. If the terrain is flat, I agree. In hilly cities, not so much.
With the way the Corona Virus is spreading we might all be wearing Face masks pretty soon. This may seem like common sense after Flint, but at this point I think a home water filter is needed for most parts of the country. Can't blindly trust the municipalities. A Home Air filter is probably needed too. Here's a growing list of things Youtube told me things one should invest: 1. Home Water Purifier 2. Air Filter 3. G…
Earlier quoted context omitted.
And what many overlook is many of these particles have nothing to do with emissions. Brake pads and tires turn to dust. So too bits of the road surface are slowly converted to fine particulates. Converting everyone to autodrive teslas powered by fusion reactors wont stop rubber from meeting asphalt. (Switching to manual transmissions would probably reduce the brake dust. Id like to see if european roads suffer as muc…
Tangential question: do trains produce fine particulates where their wheels meet the rail? I.e. is it bad to live near a train (or subway!) line?
Earlier quoted context omitted.
As well as all cars with manual transmissions.
"Engine braking" isn't just letting the engine spin down at 0 throttle. Propper engine braking, aka "Jake brake", is letting the engine spin at 100% throttle but zero fuel input (and some valve trickery). This lets air in to be compressed, releasing it before the down stroke of the piston. No car does that. It is a separate installed system on trucks. It can be almost as powerful as the engine. In a car, it could han…
When you are driving down a large hill (e.g. on a mountain) eventually the battery will become fully charged, so you can't use regenerative braking anymore. To provide some resistance so you aren't effectively driving in neutral, the car will spin the engine at high RPM without supplying any fuel (I'm not sure how this works in terms of lubrication, as I understand the fuel provides this too?). You can also engage B mode which does this at an earlier stage, so have more control without having to use the brake when driving down steep hills (like engaging a lower gear).
London hybrid busses do the same thing, as they come to a stop you can hear the engine spinning at high RPMs.
Anyone living near a busy road is swimming in particulate matter on the micrometre and nanometre scale, and particles on that scale bypass the normal defences, get into the blood stream and saturate the body. Small particles can even move down nerves, it’s really not surprising that long term exposure causes neurological problems.
And what many overlook is many of these particles have nothing to do with emissions. Brake pads and tires turn to dust. So too bits of the road surface are slowly converted to fine particulates. Converting everyone to autodrive teslas powered by fusion reactors wont stop rubber from meeting asphalt. (Switching to manual transmissions would probably reduce the brake dust. Id like to see if european roads suffer as muc…
The days of using the transmission to slow down are over. Brakes are better and more reliable (and cheaper) than ever.
Earlier quoted context omitted.
Tyre wear does release particulate matter, but it's mostly heavy, large particles that end up on the road and get washed away by weather. With the exception of tunnels, where heavy particles are constantly being churned up from the road surface and re-circulated into the air, tyre and brake wear is a relatively minor contributor to urban air pollution.
> tyre and brake wear is a relatively minor contributor to urban air pollution Why do you say that? Would love to know more, but all the research I've read lists them as significant contributors, second only to resuspension, each now exceeding tailpipe emissions on both PM 10 and PM 2.5. https://www.sciencedirect.com/science/article/abs/pii/S13522... https://dot.ca.gov/-/media/dot-media/programs/research-innov... As…
Here in London, some of the most obviously polluted and stinking roads are those where the traffic barely moves at all - lots of slow moving or idling vehicles. There isn't a great deal of brake or tyre wear when vehicles are standing still!
Earlier quoted context omitted.
> tyre and brake wear is a relatively minor contributor to urban air pollution Why do you say that? Would love to know more, but all the research I've read lists them as significant contributors, second only to resuspension, each now exceeding tailpipe emissions on both PM 10 and PM 2.5. https://www.sciencedirect.com/science/article/abs/pii/S13522... https://dot.ca.gov/-/media/dot-media/programs/research-innov... As…
Claims that tyre/brake particles exceed exhaust emissions are inevitably referring to particulate mass , not particulate count. One large particle can weigh as much as millions of nanoparticles, but is far less dangerous. Exhaust nanoparticles (sub-PM2.5) are small enough to penetrate the respiratory system, diffuse to the blood stream, and cross the blood-brain barrier. Here in London, some of the most obviously pol…
Huh, all the studies I've read and linked are comparing like with like within particle size categories. Idling considerations are addressed in the modeling too.
You seem fairly unshakable here, but the topic seems well researched and the results are pretty unambiguous to me.