Hybrids in Hilly Terrain

Started by Morris Minor, December 14, 2017, 06:13:04 AM

Soup DeVille

You don't engine brake to a stop; it doesn't work that way.

Why do i get the feeling you're missing something totally here?
Maybe we need to start off small. I mean, they don't let you fuck the glumpers at Glumpees without a level 4 FuckPass, do they?

1975 Honda CB750, 1986 Rebel Rascal (sailing dinghy), 2015 Mini Cooper, 2020 Winnebago 31H (E450), 2021 Toyota 4Runner, 2022 Lincoln Aviator

MX793

Quote from: Soup DeVille on December 15, 2017, 09:52:33 AM
You don't engine brake to a stop; it doesn't work that way.

Why do i get the feeling you're missing something totally here?

I obviously use the brakes at some point if I'm stopping.  I engine brake as much as possible.  If I see a traffic light turn yellow ahead and I know I'm going to hit it while it's still red, I let off the gas and start engine braking.  I only touch the brake pedal once speeds are low enough that engine braking isn't doing anything for me, or if there's another car ahead slowing more than I am and I can't get enough engine braking to avoid a collision.  I don't get the decel out of the VW than I do/did in any of my MT vehicles even when manually shifting the auto.  Same can be said of any auto I've driven.
Needs more Jiggawatts

2016 Ford Mustang GTPP / 2011 Toyota Rav4 Base AWD / 2014 Kawasaki Ninja 1000 ABS
1992 Nissan 240SX Fastback / 2004 Mazda Mazda3s / 2011 Ford Mustang V6 Premium / 2007 Suzuki GSF1250SA Bandit / 2006 VW Jetta 2.5

shp4man

It's easier and cheaper just to use the brakes. Long downhills are good for O/D off or lower gears, though.

Laconian

The Subaru's CVT is worthless for engine braking. It makes a lot of ugly boxer noise, but doesn't slow down the car much at all.
Kia EV6 GT-Line / MX-5 RF 6MT

CaminoRacer

A carb'd manual trans car can basically come to a complete stop without touching the brakes
2020 BMW 330i, 1969 El Camino, 2017 Bolt EV

Soup DeVille

Quote from: MX793 on December 15, 2017, 10:05:27 AM
I obviously use the brakes at some point if I'm stopping.  I engine brake as much as possible.  If I see a traffic light turn yellow ahead and I know I'm going to hit it while it's still red, I let off the gas and start engine braking.  I only touch the brake pedal once speeds are low enough that engine braking isn't doing anything for me, or if there's another car ahead slowing more than I am and I can't get enough engine braking to avoid a collision.  I don't get the decel out of the VW than I do/did in any of my MT vehicles even when manually shifting the auto.  Same can be said of any auto I've driven.

See, there it is.

I'm not talking about using engine braking to slow or stop the car, but to maintain speed on a downhill slope; since the question in the thread was about hills, I'd have thought that obvious.

I don't know why one would do as you're describing, or what the advantage is.
Maybe we need to start off small. I mean, they don't let you fuck the glumpers at Glumpees without a level 4 FuckPass, do they?

1975 Honda CB750, 1986 Rebel Rascal (sailing dinghy), 2015 Mini Cooper, 2020 Winnebago 31H (E450), 2021 Toyota 4Runner, 2022 Lincoln Aviator

FoMoJo

Quote from: Soup DeVille on December 15, 2017, 10:45:42 AM
See, there it is.

I'm not talking about using engine braking to slow or stop the car, but to maintain speed on a downhill slope; since the question in the thread was about hills, I'd have thought that obvious.

I don't know why one would do as you're describing, or what the advantage is.
Do you not downshift when coming to a stop even on level terrain?
"The only reason for time is so that everything doesn't happen at once." ~ Albert Einstein
"As the saying goes, when you mix science and politics, you get politics."

MX793

Quote from: Soup DeVille on December 15, 2017, 10:45:42 AM
See, there it is.

I'm not talking about using engine braking to slow or stop the car, but to maintain speed on a downhill slope; since the question in the thread was about hills, I'd have thought that obvious.

I don't know why one would do as you're describing, or what the advantage is.

Saves on brakes and fuel?

Clearly, if the car doesn't offer much engine braking on flat ground, it's not doing much to hold speed on downhills either.  There's a fairly large hill not far from here that, at its steepest, is roughly 10% over just shy of a mile.  Speed limit is 55.  On my MT cars, I could downshift one gear at the top of the hill, traveling 55 mph, and I might have to just touch the brakes near the bottom to keep from going over 70.  Even downshifting 3 gears at the top of the hill, I have to apply a fair bit of brake on the VW to keep it under 70 starting before I've even made it halfway down the hill.
Needs more Jiggawatts

2016 Ford Mustang GTPP / 2011 Toyota Rav4 Base AWD / 2014 Kawasaki Ninja 1000 ABS
1992 Nissan 240SX Fastback / 2004 Mazda Mazda3s / 2011 Ford Mustang V6 Premium / 2007 Suzuki GSF1250SA Bandit / 2006 VW Jetta 2.5

Soup DeVille

Quote from: FoMoJo on December 15, 2017, 10:51:23 AM
Do you not downshift when coming to a stop even on level terrain?

To stay in the proper gear, not to slow the car.

And of course in an automatic, no, no I don't. And neither does anybody else.
Maybe we need to start off small. I mean, they don't let you fuck the glumpers at Glumpees without a level 4 FuckPass, do they?

1975 Honda CB750, 1986 Rebel Rascal (sailing dinghy), 2015 Mini Cooper, 2020 Winnebago 31H (E450), 2021 Toyota 4Runner, 2022 Lincoln Aviator

Soup DeVille

Quote from: MX793 on December 15, 2017, 10:55:45 AM
Saves on brakes and fuel?

Clearly, if the car doesn't offer much engine braking on flat ground, it's not doing much to hold speed on downhills either.  There's a fairly large hill not far from here that, at its steepest, is roughly 10% over just shy of a mile.  Speed limit is 55.  On my MT cars, I could downshift one gear at the top of the hill, traveling 55 mph, and I might have to just touch the brakes near the bottom to keep from going over 70.  Even downshifting 3 gears at the top of the hill, I have to apply a fair bit of brake on the VW to keep it under 70 starting before I've even made it halfway down the hill.

Does it work at all?

Your VW would be an exception, not a rule then, and may have more to do with the engine than the transmission. As I've studiously avoided modern VWs for a few years now, so I'll have to trust you there. I've gone down the Pikes Peak road in a number of different cars, most of them automatic, and have very rarely had to use the brakes to do anything other than stop.
Maybe we need to start off small. I mean, they don't let you fuck the glumpers at Glumpees without a level 4 FuckPass, do they?

1975 Honda CB750, 1986 Rebel Rascal (sailing dinghy), 2015 Mini Cooper, 2020 Winnebago 31H (E450), 2021 Toyota 4Runner, 2022 Lincoln Aviator

MX793

There's certainly some engine braking.  Following other people in autos that don't downshift for hills, I'm probably on the brakes less.
Needs more Jiggawatts

2016 Ford Mustang GTPP / 2011 Toyota Rav4 Base AWD / 2014 Kawasaki Ninja 1000 ABS
1992 Nissan 240SX Fastback / 2004 Mazda Mazda3s / 2011 Ford Mustang V6 Premium / 2007 Suzuki GSF1250SA Bandit / 2006 VW Jetta 2.5

Soup DeVille

Like I said, I'll have to take your word for it.

But I've never driven a car, automatic or manual, that could not maintain any reasonable speed (over about 15 MPH) on any slope (that would be considered an actual road) under engine braking alone, and I would consider any car that couldn't to be dangerous.
Maybe we need to start off small. I mean, they don't let you fuck the glumpers at Glumpees without a level 4 FuckPass, do they?

1975 Honda CB750, 1986 Rebel Rascal (sailing dinghy), 2015 Mini Cooper, 2020 Winnebago 31H (E450), 2021 Toyota 4Runner, 2022 Lincoln Aviator

mzziaz

Quote from: Morris Minor on December 15, 2017, 09:16:38 AM
It's definitely an issue here: I know my brake rotors are starting to warp.

What I mean is that on those cars you can use the excess energy from going downhill to charge the battery instead of putting wear on the brakes.

http://www.youtube.com/watch?v=XjmeaufF6ZM
Cuore Sportivo

veeman

#43
This is all very interesting to me.  Having driven an MT Beetle for 3 years and putting 75,000 miles on it and currently an MT Crosstrek and putting 25,000 miles on it I rarely straight downshift from a higher gear to maintain speed or slow down when going downhill. If I'm at 80 mph on the highway and the road dips down and I want to maintain speed or slow down, I'll tap the brakes with or without the clutch until I'm at the speed I want to be.  In the Beetle if I was still above 50 mph, I'd keep it in the same 6th gear.  In the Crosstrek if I'm above 40 mph, I'd keep it in the same 5th gear (it's a 5 speed).  If it's a long and steep hill, which I rarely drive on in my commute, I'll hit the brakes and clutch until I get to the speed I want to be, and then downshift. I found that if I downshifted straight without tapping the brakes and I'm already going 65-80mph, the tach would jump to 4 or 5 thousand RPM and the engine would make a racket. 

Course I don't regularly drive very steep hills typically. 

Soup DeVille

Yes, of course one has to blip the throttle when downshifting.

One should NEVER ride the brakes to maintain speed down a hill for any amount of time.
Maybe we need to start off small. I mean, they don't let you fuck the glumpers at Glumpees without a level 4 FuckPass, do they?

1975 Honda CB750, 1986 Rebel Rascal (sailing dinghy), 2015 Mini Cooper, 2020 Winnebago 31H (E450), 2021 Toyota 4Runner, 2022 Lincoln Aviator

giant_mtb

Engine braking is friend off road.

12,000 RPM

And on motorcycle. High compression + next to no mass = only use brakes to stop
Protecctor of the Atmospheric Engine #TheyLiedToUs

AutobahnSHO

Brake to slow down, downshift to prevent speeding back up.
Will

FoMoJo

Quote from: AutobahnSHO on December 17, 2017, 10:15:40 AM
Brake to slow down, downshift to prevent speeding back up.
Poke the brake, declutch, blip the throttle, shift down, engage.  Should be as automatic as scratching our nose.
"The only reason for time is so that everything doesn't happen at once." ~ Albert Einstein
"As the saying goes, when you mix science and politics, you get politics."

AutobahnSHO

Quote from: FoMoJo on December 17, 2017, 03:16:47 PM
Poke the brake, declutch, blip the throttle, shift down, engage.  Should be as automatic as scratching our nose.

Yup. 
Will

Soup DeVille

Quote from: FoMoJo on December 17, 2017, 03:16:47 PM
Poke the brake, declutch, blip the throttle, shift down, engage.  Should be as automatic as scratching our nose.

I would think so.

Yet, one guy claims you can do 100 MPH panic stops several times a day, and your brakes will last 50,000 miles. The next replaces the rotors every 10,000 and drives normally. Then the next guy says engine braking is a gas saving technique, and several say it can't be done on an automatic.

Who knows what the next crazy thing to be said will be?
Maybe we need to start off small. I mean, they don't let you fuck the glumpers at Glumpees without a level 4 FuckPass, do they?

1975 Honda CB750, 1986 Rebel Rascal (sailing dinghy), 2015 Mini Cooper, 2020 Winnebago 31H (E450), 2021 Toyota 4Runner, 2022 Lincoln Aviator

AutobahnSHO

LOL the road in front of my house goes from the base-standard 35mph to 25mph because of some soccer fields. And it's downhill, with wide wide shoulders. It's really too low a limit so people zip up and down it at 35-40mph all day long. So the MPs like to camp at the top of the hill.

Odyssey has 3spd Auto plus Overdrive. Putting it into regular "D" doesn't slow it at all, often when I come home I shift down to "2" and it slows and maintains 26mph until the hill flattens out. No brake lights for cops. Autos do indeed engine brake if you downshift, but most people are freaked out by it because they never rev their car very high so the sudden downshift to high RPMs "isn't normal".
Will

Morris Minor

Quote from: mzziaz on December 16, 2017, 03:48:59 AM
What I mean is that on those cars you can use the excess energy from going downhill to charge the battery instead of putting wear on the brakes.
I enjoyed this review of the Nissan Leaf 2.0. The guy had a hard time adjusting to its one-pedal regen braking.
https://youtu.be/xOJyiKy0MOQ
⏤  '10 G37 | '21 CX-5 GT Reserve  ⏤

Laconian

The Outback cruise control is great. The CVT gives it a lot of flexibility to engine brake, and then it'll actually hit the brakes if the EB isn't doing the job, which happens surprisingly seldomly.
Kia EV6 GT-Line / MX-5 RF 6MT

giant_mtb

My A4 used to hit the brakes while using CC if necessary.  Wasn't programmed very well, though.  If the brakes came on, it was a jolt and not a gentle application as you'd do yourself.

Tave

Quote from: Soup DeVille on December 18, 2017, 07:10:21 AM
I would think so.

Yet, one guy claims you can do 100 MPH panic stops several times a day, and your brakes will last 50,000 miles. The next replaces the rotors every 10,000 and drives normally. Then the next guy says engine braking is a gas saving technique, and several say it can't be done on an automatic.

Who knows what the next crazy thing to be said will be?

I didn't say panic stops, I said 100mph (very slight hyperbole) to zero, which is exactly what happens in and around a lot of large cities during popular commuting times.

I agree that a lot of people fry their brakes on sustained, steep descents (like Pike's Peak you mentioned earlier). Descent control is a very good skill to practice for the health of your vehicle. I'm just saying—if the brakes can handle a 1/4-mile long 80-0 stop on the I-XX every morning; a steep residential neighborhood shouldn't have more than a minimal impact on the lifespan of the part.

I'm not aware of any cars other than hypercars which recommend 10K brake replacements.
As I write, highly civilized human beings are flying overhead, trying to kill me.

Quote from: thecarnut on March 16, 2008, 10:33:43 AM
Depending on price, that could be a good deal.

Rupert

Quote from: Soup DeVille on December 15, 2017, 09:11:25 AM
Yes, absolutely you need to shift down manually, be it tiptronic (useless in all forms), or regular AT.

Is it less? sometimes. Do you sometimes need to hit the real brakes to downshift, then let it ride? Yes; this is basic stuff though.

Who cares what gear you need to put it in? Unless you're going under about 10 MPH, there will be a gear that will hold you at a safe speed

I have noticed that generally auto trucks and SUVs are better at engine braking than cars are, so there's that.
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13 cars, 60 cylinders, 52 manual forward gears and 9 automatic, 2 FWD, 42 doors, 1988 average year of manufacture, 3 convertibles, 22 average mpg, and no wheel covers.
PRO TENACIA NULLA VIA EST INVIA

Rupert

Quote from: CaminoRacer on December 15, 2017, 10:41:42 AM
A carb'd manual trans car can basically come to a complete stop without touching the brakes

I had a couple of shitty carbed manual cars with such terrible compression that they wouldn't even stay stopped on more than a few percent grade without brakes. :lol:

Broken parking brakes, too...
Novarolla-Miata-Trooper-Jeep-Volvo-Trooper-Ranger-MGB-Explorer-944-Fiat-Alfa-XTerra

13 cars, 60 cylinders, 52 manual forward gears and 9 automatic, 2 FWD, 42 doors, 1988 average year of manufacture, 3 convertibles, 22 average mpg, and no wheel covers.
PRO TENACIA NULLA VIA EST INVIA

Soup DeVille

Quote from: Rupert on December 21, 2017, 06:44:44 PM
I have noticed that generally auto trucks and SUVs are better at engine braking than cars are, so there's that.

It generally tracks with displacement. I mean, lots of other factors are there too, but a bigger engine means more engine braking.
Maybe we need to start off small. I mean, they don't let you fuck the glumpers at Glumpees without a level 4 FuckPass, do they?

1975 Honda CB750, 1986 Rebel Rascal (sailing dinghy), 2015 Mini Cooper, 2020 Winnebago 31H (E450), 2021 Toyota 4Runner, 2022 Lincoln Aviator

giant_mtb

Quote from: Rupert on December 21, 2017, 06:44:44 PM
I have noticed that generally auto trucks and SUVs are better at engine braking than cars are, so there's that.

I've noticed this as well.  I imagine it's programming for towing/load purposes or just the nature of larger engines.